The sun is setting over Denver; is it setting on the Broncos’ season? We will learn that answer over the next 15 minutes of game time.

4:40 p.m. MST: San Francisco opens with first-and-10 at its 42. The crowd is boisterous, but its quick silence after a 7-yard Frank Gore run on the play is testament to the uneasiness that seems to permeate the 70,697 onlookers.

4:42 p.m. MST: San Francisco in the red zone after a 35-yard Alex Smith-to-Arnaz Battle pass.

4:44 p.m. MST: Good coverage and pressure from Ebenezer Ekuban and Michael Myers forces Smith to roll left and settle for a toss out of bounds and away from danger. Joe Nedney salvages a 29-yard field goal, however, and the Broncos trail 20-16.

4:47 p.m. MST: First-and-10 from the Denver 28, 11:51 to go, and the Broncos out of timeouts, which could dramatically alter the decisions that follow throughout this period.

4:50 p.m. MST: Mike Nolan challenges the Broncos’ 15-yard Jay Cutler-to-Tatum Bell screen pass. It appeared as though Bell lost the football before hitting the ground. The question is … does replay show that the 49ers definitively recovered it? This play would have been unchangeable a year ago, but the league’s replay regulations were modified in the offseason to allow for reviews of fumbles after the whistle blew.

4:55 p.m. MST: Walt Harris picks the ball up well after the play after Bell fell on the football. What will Larry Nemmers rule?

4:56 p.m. MST: Forty Niners ball, according to Nemmers. Bell laid upon the ball for a second or two. Harris looked like he picked up the football simply to hand it to umpire Undrey Wash. Yet Harris’ casual little procurement — which seems merely like a bit of courtesy to keep an official from kneeling to get the football — gives the 49ers the football at the precipice of scoring position.

5:00 p.m. MST: “Broncos ball, Broncos ball,” chants the crowd after the officials discuss a Smith-to-Taylor Jacobs pass that sees Karl Paymah strip him of the football, pick it up and — eventually, after some prodding from John Lynch — take off.

5:04 p.m. MST: Nemmers still looking in the replay apparatus.

5:05 p.m. MST: Now it’s ruled incomplete. Jacobs took three steps before hitting the ground and losing the football. “How that can be an incomplete pass, I have no idea,” says KOA’s Dave Logan.

5:09 p.m. MST: Third-and-7 from the Denver 9 for the Broncos … and Cutler’s pass for Rod Smith is incomplete for a costly three-and-out. Just 8:44 remains in the game now.

5:11 p.m. MST: Denver needed a booming punt, and Paul Ernster couldn’t deliver, with a 35-yard punt that had a net of just 32 after the return. One play later, Frank Gore has the 49ers in scoring position after a 12-yard run to the Denver 29.

5:13 p.m. MST: Frank Gore up to 119 yards on the ground. San Francisco down to one timeout after Smith can’t get the play off before the snap. Forty Niners face third-and-8 from the Denver 27 after the timeout.

5:15 p.m. MST: Smith in the shotgun … flags fly as San Fran’s Adam Snyder is whistled for a false start.

5:16 p.m. MST: Karl Paymah in good coverage on Jacobs … incomplete in the end zone. Joe Nedney on to attempt a 51-yard field goal … three flags fly as Ebenezer Ekuban was called for a flinch that supposedly caused a Niners lineman to false start. Ekuban took a knee, the Niners reacted, and the five-yard penalty makes it a 46-yard attempt, which Nedney nails. Denver trails 23-16.

5:19 p.m. MST: With a seven-point deficit and no timeouts and 80 yards between his team and the end zone, the Broncos face their biggest possession of the season. It begins with a 3-yard Mike Bell run on first-and-10.

5:20 p.m. MST: Cutler finds Javon Walker, but the ball skips in and out of the wideout’s hands.

5:21 p.m. MST: False start, Denver, Erik Pears. Now third-and-12. The situation grows a little more grim.

5:22 p.m. MST: Mike Bell behind Rod Smith, Ben Hamilton and Tony Scheffler for a 24-yard catch-and-run that puts a little CPR into the Broncos’ season.

5:23 p.m. MST: Bell for eight more yards. Broncos taking their time, huddling between plays. Clock down to 4:10.

5:24 p.m. MST: Cutler to Walker for three yards. First-and-10 from the San Francisco 47. The crowd seems nervous and tight.

5:25 p.m. MST: Cutler for David Kircus, 11 yards, first down to the 36. Less than three minutes remain.

5:26 p.m. MST: A draw play to Mike Bell gains just one yard. Denver huddles before second-and-9. Cutler with a straight drop, and locates Brandon Marshall across the middle at the San Francisco 16. Two-minute warning.

5:28 p.m. MST: Mike Bell does it by himself for seven yards on a screen for Cutler. Clock ticking, down below 1:40. No huddle for the Broncos.

5:28 p.m. MST: Touchdown, Tony Scheffler. PAT is good.

5:29 p.m. MST: Did the Broncos leave too much time for a response? Ninety seconds remain.

5:30 p.m. MST: The rookies got the Broncos to the end zone. It’s now up to the veterans on defense to keep the 49ers out of field-goal range. Fingernails are down to nubs from Grand Junction to Jefferson City as the Chiefs and Broncos’ fans sit nervously awaiting this result.

5:31 p.m. MST: Kickoff return to the San Fran 34. That continues to be a bugaboo.

5:32 p.m. MST: Niners with second-and-5 from the 39. Smith under center. Blitzed by a horde of Broncos; there’s bringing the house, but that was bringing the mansion … Smith tosses it softly for Gore, who can’t quite hang on.

5:33 p.m. MST: Handoff to Gore, who is three yards short of the first down. Five seconds difference between the game clock and play clock.

5:34 p.m. MST: Overtime. “We will toss the coin at midfield for the overtime.” Where else would it be tossed — in the tunnel? In the broadcast booth?

5:35 p.m. MST: San Francisco calls heads. It is tails — for a second coin toss today.

5:39 p.m. MST: Crowd going bonkers as overtime begins. Nedney’s kickoff sails 71 yards and is returned 28 yards.

5:40 p.m. MST: Flanker screen to Marshall goes for just one yard — although it actually went about a foot … Second-and-9, and Smith takes the pass and runs right for the sticks. First down.

5:41 p.m. MST: Back-to-back plays to Mike Bell up the middle leave Denver about a yard and a half short of the first down … third-and-a-long-1 from the Denver 46. Bell collided with Bryant Young on the second of those carries; Bell stays in while Young leaves, a little shaken up.

5:42 p.m. MST: Bell loses his footing as he takes the handoff … he nearly lost the ball, but falls on it. That leaves fourth-and-4 from the 43, and sends Paul Ernster onto the field to punt.

5:43 p.m. MST: Ernster uncorks a 46-yard punt … nice and high, fair caught. Just what the Broncos desperately needed. Crowd chanting “Defense.” Most of the spectators are on their feet.

5:43 p.m. MST: Gore picks up six yards on first down — right up the middle.

5:44 p.m. MST: First down, Niners after Smith finds Gore for six more yards.

5:46 p.m. MST: Another first down as Smith finds Michael Robinson open across the middle to the 49ers 40. About 25 yards away from field-goal range now.

5:47 p.m. MST: Now to midfield after Gore slams 10 yards up the left side. With injuries all around, the defense might be a little tired.

5:48 p.m. MST: Heavy doses of Gore now. Six yards up the middle.

5:48 p.m. MST: Gore can’t get anywhere as he looks to bounce outside. Third-and-4 from the 44 upcoming … biggest play of the year for the Broncos.

5:48 p.m. MST: Smith blitzed. His throw overshoots everyone. The “incomplete” chant has rarely sounded louder.

5:49 p.m. MST: With 7:01 left, Kircus calls for the fair catch at the Denver 11. Broncos desperately need at least a couple of first downs here to at least get some field position.

5:50 p.m. MST: Cutler’s first-and-10 pass is tipped at the line of scrimmage. Mike Bell slams forward for six yards on second down. Monstrous third-and-4 play awaits.

5:51 p.m. MST: Cutler for Walker … huge lunge by Walker for the first down.

5:52 p.m. MST: Tatum Bell back in the game … he gets two yards on a screen pass. Clock down to 5:15. Broncos taking their time between plays.

5:53 p.m. MST: Clock down to 4:52 as flags fly … false start on Ben Hamilton puts the Broncos back at their 19 with second-and-13.

5:53 p.m. MST: Forty Niners call timeout.

5:54 p.m. MST: Cutler for Brandon Marshall … he dives for the ball, and can’t quite hang on. Instead of first-and-10 at the 40, it’s third-and-13 from the 19. Clock stopped with 4:45 left.

5:55 p.m. MST: Ernster needs another punt like he uncorked earlier in overtime … and he gets it, but Brandon Williams returns it to the 49ers 39. The net yardage is 42.

5:57 p.m. MST: First-and-10 from the 39 … and a reverse gets the 49ers to the Denver 41.

5:58 p.m. MST: Smith under pressure and throws incomplete to the left side. Crowd on its feet, but nervous.

5:58 p.m. MST: Second-and-10 from the Denver 41 … Gore goes left out of the I-formation for two yards.

5:59 p.m. MST: Third-and-8 from the Denver 39 … the way Nedney has been booming it on kickoffs, this IS field-goal range … but it’s academic after a 14-yard completion to Gilmore in front of Karl Paymah. Just 3:16 remains in overtime … and possibly the Broncos’ season.

6 p.m. MST: I-formation … Gore up the middle for four yards to the 21. The stadium is deathly silent after that run. Some spectators have turned and headed towards the exits.

6:01 p.m. MST: Gore up the middle for three more. Two-minute warning.

6:03 p.m. MST: Niners choose to kick on third down. Nedney, a former Bronco, sticks the stake in the heart of his former team with a 36-yard field goal. Ballgame, Broncos lose, 26-23.

Back for the third quarter after downing a couple of magnificent halftime cookies …

4:01 p.m. MST: Still no Al Wilson on the field; Nate Webster remains at middle linebacker … San Francisco’s offense right now seems to consist of getting it to Frank Gore or playfaking to the Pro Bowl tailback before looking downfield. It appears to be working, as the 49ers offense has awoken from its early-game slumber.

4:06 p.m. MST: San Francisco has converted both of its third-down plays early on this drive after being successful on three of nine third downs before intermission. Michael Robinson ran through a Domonique Foxworth tackle attempt for the Niners’ second first down of the half, and San Francisco is at midfield four minutes into the half.

4:10 p.m. MST: Niners now three-of-three on third downs for this drive, and their possession has consumed more than six minutes. This is getting troublesome for the Broncos.

4:12 p.m. MST: Four-of-four, and a touchdown. Denver’s lead is now just 13-10.

4:16 p.m. MST: Jay Cutler is back in the game.

4:18 p.m. MST: Two plays in, and Cutler’s looking downfield, although his shot for Javon Walker was underthrown. Walt Harris had some contact with Walker, but no call was made.

4:19 p.m. MST: The theme of the quarter is third-downs … the Broncos came into the half 0-for-5, and looked to have their first third-down conversion of the day before Stephen Alexander was called for holding, nullifying Cutler’s third-and-7 completion for Brandon Marshall.

4:20 p.m. MST: Disaster strikes as the holding penalty leads to a third-and-17, where Brandon Moore gets pressure up the middle, leading to Cutler throwing as he backpedals, spawning an errant toss for Alexander that Walt Harris corrals and turns into a touchdown that puts the Broncos down for the first time today.

4:24 p.m. MST: Special teams creates some more good field position — to midfield after Quincy Morgan’s 49-yard kickoff return. Cutler quickly finds Rod Smith for 15 yards and a first down. Broncos on the move on what could be a vital drive for their chances of keeping their season alive.

4:26 p.m. MST: A Tony Scheffler catch gets Denver to the 49ers 24, but a Tatum Bell false start pushes the Broncos back five yards. It is the second false-start penalty against someone in the Denver backfield today.

4:29 p.m. MST: Back-to-back catches by Rod Smith have the Broncos at the 49ers 5. But they’ve used two of their three timeouts on this possession.

4:32 p.m. MST: Mark Roman clobbers Cutler from the blind sidze on second-and-goal from the 5; they now face third-and-goal from the 14 … and with the play clock draining, Cutler calls the Broncos’ final timeout, to a chorus of boos from the stands.

4:34 p.m. MST: Another goal-to-go situation, another field goal. Denver trails, 17-16.

4:36 p.m. MST: Darrent Williams questionable to return with a left-shoulder injury. With Curome Cox also injured, Denver will be forced to rely upon Karl Paymah at one cornerback slot and Hamza Abdullah at safety when Domonique Foxworth slides down to handle nickel-back duties. The crowd is loud, but the Broncos are increasingly battered as the quarter concludes.

4:38 p.m. MST: Denver’s third-down defensive struggles continue in the second half; the 49ers are now 5-for-5 after a 5-yard Alex-Smith-to-Taylor Jacobs pass on third-and-4.

Second-quarter notes:

2:53 p.m. MST: Darrent Williams jars the return game to life, going right, darting, dodging, shaking, baking and finally sprinting his way to a 32-yard return that gives the Broncos more good drive-starting field position at their 41-yard-line.

2:57 p.m. MST: our weeks after being benched, Jake Plummer is about to step back onto the field after Jay Cutler absorbed a chin-strap-rattling hit from the right side.

3:01 p.m. MST Mike Bell got the Broncos into a second goal-to-go situation, but the doings haven’t been so good since … a sack, an incompletion, and a quarterback draw for three yards on third-and-goal from the 6.

3:03 p.m. MST: Jay Cutler “got his bell rung,” according to the official report from vice president of media relations Jim Saccomano. He is probable to return. The Broncos, meanwhile, lead 6-0.

3:11 p.m. MST: Curome Cox — or as the press-box public-address announcer said, “Courteney Cox” — was slow to arise after a punt return. Jake Plummer, meanwhile, remains in at quarterback.

3:13 p.m. MST: Tatum Bell becomes the sixth man to post a 1,000-yard rushing season in the last 12 seasons. The Broncos have now had 11 1,000-yard rushing campaigns since 1995.

3:15 p.m. MST: Jake Plummer rolled left, looked deep for Javon Walker — but his pass finds Walt Harris after Walker gets entangled and hits the field. San Francisco now takes over at the Denver 39 at a 42-yard return.

3:17 p.m. MST: The game has turned a bit balky on both sides in the last few minutes, with a flow as smooth as the engine for a ’79 Pacer on a cold day. Elvis Dumervil and Ebenezer Ekuban do something to bring the chilled fans to their feet, sacking Smith for a seven-yard loss on third-and-10 from the Denver 39.

3:23 p.m. MST: With third-and-6 from its 18, Plummer is called for a false start. Tatum Bell gets the call on third-and-11, gaining 10 yards before being stopped just shy of the sticks, focing a Paul Ernster punt that covers 45 yards.

3:29 p.m. MST: Even when you don’t throw at Champ Bailey, he still makes a play. San Francisco quarterback Alex Smith spent the game’s first 27 minutes avoiding the Pro Bowl cornerback. The ball, though, still found Bailey after it bounced off Frank Gore and into Bailey’s grasp. It’s his 10th interception of the season and gives the Broncos a 13-0 lead. The season total is the highest for the Broncos since Austin “Goose” Gonsoulin, one of the original Broncos on the 1960 roster.

3:36 p.m. MST: Some big plays by Darrent Williams — first to break up an end-zone shot, then to tackle San Francisco tight end Eric Johnson in the open field two yards short of the first down with 1:03 left in the half.

3:39 p.m. MST: Alex Smith resuscitates the drive with a fourth-and-2 run for a first down. San Francisco in the no-huddle by necessity with just one timeout left and 31 seconds remaining before halftime.

3:43 p.m. MST: Kenard Lang just had a chance to fall on a football that Alex Smith fumbled, and couldn’t gain possession. That gives the 49ers a chance to pierce the scoreboard for the first time today; the reprieve allows them to get Joe Nedney onto the field for a 46-yard field goal.

Let’s start this a few minutes early …

2:04 p.m. MST: As INVESCO Field sits bathed in flood of welcome sunlight, it’s time for Jacksonville to call Rescue 411. Larry Johnson’s NFL single-season-record 411th carry just gave the Chiefs a crucial first down with 2:21 remaining to drain a little more hope from the Jaguars’ reserves. It appears as though the Broncos will definitely need a win to get into the playoffs.

2:06 p.m. MST: Michael Bennett recovers his own fumble for Kansas City, allowing the Chiefs to keep possession for a third-and-1. Jacksonville is now down to one timeout, so the Chiefs need barely 36 inches to force the Broncos into a win-or-die situation.

2:08 p.m. MST: First down, Chiefs and Larry Johnson. For all intents and purposes, that’s game.

2:13 p.m. MST: San Francisco calls heads, and the coin toss comes up tails. Denver will start the game on offense.

2:16 p.m. MST: Denver opens with one tight end (Tony Scheffler) out of the I-formation, with Tatum Bell at tailback and Kyle Johnson at fullback. Jay Cutler finds Scheffler wide open across the middle on a playfake for 29 yards to open the game.

2:18 p.m. MST: In the end, the Broncos’ chances of backing into the playoffs ended on a Jaguars offsides penalty. Denver must earn its way in and has advanced to the San Francisco 35 on its opening drive, but faces third-and-9.

2:19 p.m. MST: Denver elects to punt from the 49ers 35 after a third-down incompletion. Paul Ernster’s pooch of a punt hits Karl Paymah before Mike Leach downs it; the 49ers will start their opening drive at their 2.

2:21 p.m. MST: Al Wilson is active, but Nate Webster makes the start at middle linebacker.

2:22 p.m. MST: Third-and-seven sees the Broncos in the nickel and D.J. Williams and Ian Gold as the two linebackers. Frank Gore’s three carries go for five yards on the series, and the Broncos end up with a net loss of six yards on the exchange of punts, although they will begin at the 49ers 41.

2:25 p.m. MST: Shawntae Spencer was unblocked on a corner blitz from the left side, and Cutler appeared to have no clue that the defender was closing in on him. However, Cutler held onto the ball, and has done a great job of holding onto the football the last two games after losing his grip on it five times in his first two starts. Denver goes three-and-out.

2:30 p.m. MST: Webster still in at middle linebacker … John Lynch picks up where he left off last week, stopping Vernon Davis on an end-around to force the 49ers into second-and-14 after they got their initial first down of the game.

2:32 p.m. MST: San Francisco gets 12 yards on its next two plays, but calls for a punt … and a fake thereof. Denver diagnosed it perfectly, as Ian Gold scuttled the shovel pass, giving the Broncos splendid field position once again at the San Francisco 40.

2:36 p.m. MST: From one extreme to the other … Cutler throws into traffic and is nearly intercepted by Jeff Ulbrich … but from the near-debacle comes a 15-yard gain after Mark Roman slams into Scheffler after the pass had been tipped away. It’s an unnecessary-roughness penalty, and the Broncos are in field-goal range.

2:39 p.m. MST: The 49ers defense has given the Broncos nearly all the yardage it has gained so far on this drive — 15 yards for unnecessary roughness and 12 yards on a roughing-the-passer infraction. Denver has first-and-10 from the 11 … perhaps my favorite red-zone situation, since you can potentially have eight plays to go 11 yards.

2:43 p.m. MST: It’s six plays, since Tatum Bell gained the first down in two carries. But his two runs are followed by an aborted run play where Mike Bell couldn’t get out of the backfield and a fumbled snap that Cutler falls upon at the 2. Mike Bell promptly loses three yards as Jeff Ulbrich takes him down around the chest.

2:44 p.m. MST: That is the first time all year that the Broncos have failed to score a touchdown in a goal-to-go situation. Jason Elam’s kick puts the Broncos up 3-0.

2:46 p.m. MST: An ugly, low line-drive of a kickoff allows the 49ers to start with their best field position of the day, at their 37-yard-line with 37 seconds left in the quarter.

Warm New Year’s greetings from INVESCO Field at Mile High, where the skies are clear and the field in magnificent shape considering the meteoroogical pounding that the region has absorbed in the last 10 days.

Linebacker Al Wilson will play after being listed as questionable throughout the week and missing practice outright Wednesday and Thursday and sitting out part of it on Friday with back spasms that settled in after last week’s win over the Bengals. Fellow ‘backer Keith Burns, however, was scratched from the lineup for today’s game, having dealt with a hand injury over the past week.

Denver’s seven other inactives include wide receiver/kickoff returner Brian Clark, running backs Damien Nash and Cedric Cobbs, guard Chris Kuper, tight end Chad Mustard and defensive linemen Kenny Peterson and Antwon Burton.

San Francisco’s eight inactive players include starting linebacker Derek Smith and starting tackle Jonas Jennings.

Meanwhile, though, the attention of press-box onlookers remains riveted upon the doings in Kansas City, where the Chiefs lead the Jacksonville Jaguars 35-17 midway through the third quarter. In effect, the Broncos’ chances of making the playoffs before kickoff today rest upon the callow arm of Quinn Gray, brought in at halftime to replace
David Garrard.