With the No. 1 seed in the AFC on the line for Denver, Broncos coach Gary Kubiak decided to put the ball in Peyton Manning's hands.

The 39-year-old quarterback, who went into Sunday's game as a backup for the first time in 21 years, finished the game for the Broncos after Brock Osweiler was benched in the third quarter.

Manning came in with the Broncos trailing 13-7 and immediately brought Denver back. Manning led Denver to points on four of the first drives that he played, a total that included two touchdown drives. 

In the end, Manning did just enough to help the Broncos to a 27-20 win. The aging quarterback finished 5 of 9 for 69 yards in the game. 

Manning came in because Osweiler was benched after struggling for more than two quarters against the Chargers. During his time on the field, Osweiler threw two interceptions and the Broncos turned the ball over a total of five times.

After Denver scored on its opening drive with Osweiler, the Broncos did nothing on their next eight drives, which prompted Kubiak to bring in Manning. 

During his first drive on the field, Manning immediately directed an eight-play, 80-yard drive that gave the Broncos a 14-13 lead over the Chargers. Manning went 2-for-2 for 20-yards on the drive. Not only was he perfect on his two passes, but Manning also checked out of several play calls, which created running room for C.J. Anderson. Anderson carried the ball three times for 45 yards and a touchdown on the drive. 

Manning's first completion was the first pass he's attempted since Week 10, when he was benched after throwing three interceptions in a loss to the Chiefs. Manning was diagnosed with a foot injury shortly after that and Osweiler was named the team's starting quarterback.

Now, it looks like things will be up in the air as the Broncos head to the postseason. 

Since Denver won, Kubiak will now have two weeks to pick his starter because the Broncos will have a first-round bye. The Broncos coach has said since November that if Manning was 100 percent healthy, then he'd be the starter. Manning will now have two weeks to get to 100 percent, so don't be surprised if he's starting when the Broncos open the postseason. 

To read more about Manning's return, you can check out the recap from our CBSSports.com Game Tracker here

Peyton Manning is back at quarterback for the Broncos. (CBS)
Peyton Manning is back at quarterback for the Broncos. (CBS)