Brandon McManus kicked a game-winning 53-yard field goal as time expired and rookie quarterback Drew Lock passed for two touchdowns in his NFL debut to lift the host Denver Broncos to a 23-20 victory against the Los Angeles Chargers on Sunday afternoon.Denver (4-8) snapped a two-game losing streak, while Los Angeles (4-8) lost its third straight.McManus’ field goal followed a 37-yard pass interference penalty against the Chargers, and it was the third field goal in the game’s final 4:26.The second of those three came when the Chargers tied the game at 20 on a 46-yard field goal by Michael Badgley with 14 seconds remaining. Los Angeles converted a 4th-and-11 from its own 24 with 2:22 left to keep the drive alive, and then quarterback Philip Rivers found Mike Williams down the left sideline for a 38-yard completion.McManus had kicked a go-ahead 52-yard field goal with 4:26 remaining to put the Broncos ahead 20-17.Lock finished 18-for-28 passing for 134 yards, two touchdowns and one interception. Rivers was 20-for-29 for 265 yards, two touchdowns and one interception.Lock shined at the outset, throwing a pair of first-quarter touchdown passes to Courtland Sutton to help the Broncos take a 17-10 lead into halftime.Lock’s first scoring pass came about as the result of a savvy end zone adjustment from Sutton, who avoided contact from Chargers cornerback Casey Hayward Jr. with his left hand while corralling the 26-yard TD pass from Lock with his right.