DENVER -- Quarterback Peyton Manning helped turn coach Gary Kubiak's gut feeling into a winning move.
Cast in the unfamiliar role of backup, Manning came off the bench to relieve an ineffective Brock Osweiler and led four second-half scoring drives, and the Denver Broncos rallied to beat to the San Diego Chargers 27-20 on Sunday. The victory clinched the AFC West title and the conference's No. 1 playoff seed.
"It's been a different year certainly, a different week, different approach," Manning said. "I think when I was in there, we ran the ball better. We held on to the ball, caught the ball better. That's just kind of how it worked out."
Relying more on his leadership and steadying influence than his passing arm in his first action in seven weeks, Manning drove the Broncos (12-4) to a pair of field goals by kicker Brandon McManus and on marches that ended in touchdown runs by C.J. Anderson and Ronnie Hillman.
"He told us to go out and put some points on the board and that's what we did," wide receiver Demaryius Thomas said of Manning. "He told everyone to calm down. He came in and was the leader that he is."
Hillman finished with 117 rushing yards, including a tiebreaking 23-yard touchdown run with 4:44 left to play on the first play after safety Shiloh Keo's interception of a pass from quarterback Philip Rivers. The throw deflected off the hands of wide receiver Tyrell Williams, who earlier caught a touchdown pass.
The Broncos, defense stopped San Diego's final possession on downs, and Manning took a knee to run out the final few seconds.
"Maybe we played really good considering all the elements, but we gave them all they wanted," Rivers said. "But we lost, so that goes for naught. It's just sickening losing like this."
Added Chargers coach Mike McCoy: "Well, if that game doesn't summarize our season, I don't know what does."
Kubiak said he decided to go with Manning after the Broncos were set back by their fifth turnover of the game during the third quarter.
"Just my gut told me to turn it over to him," Kubiak said. "I'm just very proud of him. He's worked really hard to stay there for us and it couldn't be a bigger day to be there for us."
"It lifted the whole stadium," Broncos cornerback Aqib Talib said of Manning's insertion into the game. "It lifted the O-line. The O-line got with it and we opened up some holes and got to running that ball. I don't know if it as just his presence, but it was just a little energy that came through the building."
Greeted by roaring crowd, Manning led a drive that leaned on the running of Anderson with a couple of key completions along the way. Anderson's 1-yard scoring run with 5:24 left in the third gave Denver a 14-13 lead.
McManus added a 48-yard field goal for Denver before the Chargers regained the lead on Rivers' 80-yard scoring pass to Williams, who somehow was all alone downfield for the long-distance touchdown that put San Diego back on top 20-17 with 12:58 to play.
Again, Manning led the Broncos to a score, as McManus' 35-yarder capped a 63-yard drive and tied the game 20-20 with 9:48 to go.
Midway through the third quarter, San Diego (4-12) surged in front following the Broncos' fifth turnover of the game, a fumble by Anderson that was recovered by the Chargers at the Denver 32-yard line. Four plays later, tight end Antonio Gates reached over Keo to grab a 13-yard touchdown pass from Rivers and gave San Diego a 13-7 lead.
With Denver trailing for the first time and its playoff seeding hanging in the balance, coach Gary Kubiak made the call to bench Osweiler in favor of Manning, who was active for the first time since leaving a loss to the Kansas City Chiefs on Nov. 15 with a foot injury and after throwing four interceptions.
Manning finished 5-for-9 for 69 yards Sunday. Osweiler was 14-for-22 for 232 yards with one touchdown pass and two interceptions.
The Broncos dominated play in the first half but clung to a 7-6 lead at halftime. Denver committed four first-half turnovers, including three by Osweiler on a pair of interceptions and a fumble after a sack.
NOTES: Chargers were without S Eric Weddle, who went on injured reserve this week with a groin injury. San Diego also was without CB Jason Verrett, who was among the team's inactive players because of a hamstring injury. ... Broncos S Darian Stewart (hamstring) left the game after breaking up a first-quarter pass intended TE Antonio Gates. He did not return. ... With his first-quarter TD catch, Denver WR Demaryius Thomas moved pass Ed McCaffrey into sole possession of third place on the Broncos' all-time list with 47 career scoring receptions. ... Chargers WR Malcom Floyd, playing his final game before retiring, left the game in the first half after sustaining a concussion. ... The Chargers were down to third string at left tackle.