DENVER — In the days ahead of the Broncos’ Week 13 game against the Chargers, Head Coach Vic Fangio offered hints that Drew Lock could make his first career start.

The Broncos made no formal announcement ahead of kickoff, but Lock trotted out with the starting offense to begin the game — and that’s when the show began.

In his first start, Lock threw a pair of first-quarter touchdowns to Courtland Sutton to give the Broncos an early lead, and he led a one-play, game-winning drive against Chargers’ fifth-ranked defense to secure a 23-20 win.

Lock finished the game 18-of-28 for 134 yards, two touchdowns, one interception and a 84.5 quarterback rating. He also found Sutton for a game-changing pass-interference call on the final drive of the game — a play that will not show up on Lock’s stat line.

He is the first quarterback drafted by the Broncos to win his first start as a rookie since Gary Kubiak won his debut in 1983.

The Chargers rebounded from a 17-3 deficit to tie the game with 12:18 remaining in the fourth quarter and then again with 14 seconds to play, but Lock and the offense set up McManus’ game-winning kick with no time remaining.

The rookie quarterback’s only interception came with 11:41 to play in the fourth quarter, but Derek Wolfe sacked Philip Rivers to force the Chargers to settle for a 55-yard field-goal attempt. Michael Badgley missed the ensuing 55-yard field-goal attempt, which kept the game tied at 17.

These are the players and plays that helped Denver improve to 4-8 on the season and sweep their AFC West rival for the first time since 2015.

Game-changing moment

When Lock threw an interception with 11:30 to play in the fourth quarter, the Broncos’ outlook looked bleak. The team had squandered a 17-3 lead, and Rivers and the Chargers had scored a touchdown on their previous drive to tie the game. Denver’s defense, however, came up big. Wolfe recorded a 7-yard sack to push Badgley’s field-goal to 55 yards, and Los Angeles’ kicker missed. The Broncos retook the lead on the ensuing drive, but they still needed one more stop from their defense.

The Chargers converted a fourth-and-11 with just over two minutes to play to move the ball into Denver territory, but the Broncos forced a field goal that tied the game at 20.

Then, with nine seconds remaining, the Broncos’ offense took a shot down the field instead of playing for overtime. Sutton drew a 37-yard pass interference penalty on cornerback Casey Hayward Jr., and McManus knocked in a 53-yarder to earn the 23-20 win.

Memorable highlight

In Week 9, Courtland Sutton leaped in the air in the right corner of the south end zone to pluck a pass out of the air and give Brandon Allen his first career touchdown pass. This week, Sutton did the favor for Drew Lock. With 4:33 to play in the first quarter, Lock tossed the football into the same corner of the end zone, and Sutton dove forward while hauling in the pass with one hand. It might’ve been Sutton’s best catch of the season, and it gave Lock his first career touchdown pass.

Defining statistic

7-of-15.

The Broncos entered Sunday’s game with the 30th-ranked third-down defense in the NFL, as the team had converted just 27.7 percent of its third-down attempts on the season. But Sunday was different. Led by Lock, the Broncos converted 7-of-15 third down, a 46.7 percent conversion rate. The Broncos got off to a tremendous start in the category, as they converted 5-of-6 third downs in the first quarter.

Top performers

Lock and Sutton earn nods for their two touchdown connections in the first quarter that gave Denver an early 14-0 lead. Phillip Lindsay added 58 rushing yards — including 13 on the Broncos’ penultimate drive — to help the Broncos regain the lead for good. Defensive end Derek Wolfe sacked Rivers twice in the game to push his season total to seven sacks, which is the highest single-season output of his career. Will Parks recorded the first sack of his career, and rookie defensive lineman Dre’Mont Jones snagged the first interception of his career in the first quarter when Rivers tried to throw a screen pass. Brandon McManus added field goals of 52 and 53 yards.