It took the Broncos two-and-a-half quarters to unLock their offense.
When they did, they came roaring back from a 21-point deficit in the third quarter and beat the Chargers, 31-30, on a one-yard touchdown pass from Drew Lock to KJ Hamler with no time left in the fourth quarter.
Brandon McManus hit the PAT to give the Broncos the win.
The Broncos offense nowhere to be seen while the Chargers built a 14-3 halftime lead. They stretched it to 21-3 on a 24-yard touchdown pass from Justin Herbert to Mike Williams at the 10:13 mark of the third quarter.
Michael Badgley's 52-yard field goal pushed the Chargers advantage to 24-3 with 7:33 left in the third.
But then things clicked for the Broncos.
The Broncos responded to Badgley's field goal with a five-play, 75-yard scoring drive. Phillip Lindsay's 55-yard touchdown run with 6:05 left in the third quarter brought the Broncos to within 24-10 and the comeback was on.
The Broncos closed the gap to 24-17 on Albert Okwuegbunam's 9-yard touchdown catch with 11:42 remaining in the third quarter.
That started a string of trading touchdowns for field goals.
Michael Badgley's 47-yarder made it 27-17 L.A. with 7:57 remaining.
But the Broncos quickly answered with a two play, 75-yard drive capped by Lock's 40-yard touchdown strike to DaeSean Hamilton. Denver was down 27-24 halfway through the fourth quarter.
The Chargers again kicked a field goal, with Badgley hitting from 33 yard out to make it 30-24 with 2:30 left.
That was just enough time for Lock, who engineered the game-winning 14-play, 81-yard drive that took every last second on the clock.
Lock found KJ Hamler on the right side of the end zone on a one-yard pass with no time left to tie the game at 30.
McManus' kick gave the Broncos a stunning 31-30 win.
Lock completed 9-of-12 passes for 46 yards on the final drive and the Broncos benefited from two pass interference calls on the Chargers. The second one came against Okwuegbunam in the end zone and put the ball at the one-yard line with one second to go.
The Broncos have won three of their last four games and are 3-4 this year. They play at the Falcons on Sunday, November 8. Coverage starts with the BetFred Opening Line at 7 a.m. mountain time on KOA NewsRadio 850 AM and 94.1 FM.
KOA postgame interviews with Broncos quarterback Drew Lock, wide receiver KJ Hamler and head coach Vic Fangio are below, along with video highlights.