Trailing by 14 points with 4:14 remaining, the Chargers drove 80 yards on eight plays, scoring a touchdown on a 21-yard pass to Danario Alexander 1:24 remaining in the game.
It was Alexander’s fourth catch of the drive, totaling 65 yards.
Running back Ryan Mathews made the biggest play of the series with a 24-yard reception that moved San Diego across midfield.
With two timeouts remaining, the Chargers attempted an onside kick that tight end Virgil Green recovered for the Broncos.