DENVER -- Philip Rivers outdueled Peyton Manning the hard way.
Throwing for two touchdowns and leading methodical, clock-eating drives to keep the ball away from Denver's explosive offense, the Chargers quarterback led San Diego to a 27-20 upset win over the Denver Broncos on Thursday night.
Rookie wide receiver Keenan Allen caught touchdown passes of 19 and 10 yards from Rivers, who completed 12 of 19 passes for 166 yards passing in helping San Diego (7-7) keep alive its hopes for a playoff berth.
"We converted third downs when we had to," Rivers said. "We didn't make any unbelievable plays, but we made the plays we had to make. It's just kind of how the game went."
San Diego's Ryan Mathews ran for 128 yards and a touchdown on 29 carries. He became the first running back to surpass 100 yards rushing against Denver's defense this season.
"That's an awesome team," San Diego wide receiver Vincent Brown said of the Broncos. "They've already proven what they can do. For us to come in here and do what we did says a lot about us."
Manning, Denver's quarterback, completed 27 of 41 passes for 289 yards passing with touchdown throws of 15 yards and 5 yards to wide receiver Andre Caldwell. However, the Broncos' league-leading offense was held to a season low in points.
"We didn't have our best stuff tonight," Broncos coach John Fox said. "I thought our guys battled back in the second half, but we couldn't get off the field enough on third down and we couldn't stay on the field enough on third down. They had a good plan and executed it."
On the surface, part of the plan was keeping the ball away from Manning and an offense that, coming in, scored at least 25 points in 18 consecutive games, including three games this season in which Denver topped 50 points.
San Diego averaged just under 10 plays in each of its first four scoring drives and finished with a nearly 2-to-1 advantage in time of possession (38:49 to 21:11).
Rivers insisted the Chargers didn't set out to control the clock. That was just the way it worked out.
"I can promise you, we didn't mention one word about time of possession this week," he said. "We mentioned we've got to score. We've got to score touchdowns and not field goals. We didn't do it every time, but we did it a couple of times that were key. We scored 14 points without their offense playing, other than three or four plays before the half."
The Broncos (11-3) saw their 10-game winning streak against fellow AFC West teams end. They also lost for the first time in five meetings with the Chargers.
"We just weren't as sharp as we needed to be," Manning said. "We didn't have the ball that much, and when we did, we didn't do enough with it. Give San Diego credit. It's a division loss. It's disappointing that we got beat by a team that played better than us today."
What the Chargers said
"We can't control the rest of the league. All we can do here in the San Diego Chargers' organization is play our best football week in, week out, try to improve, and then, hey, everything else will take care of itself at the end of the road." -- Coach Mike McCoy, on the team's playoff prospects.
What the Broncos said
"He's an elite quarterback in this league. He's won in this league, and he's a vet. He did a good job of mixing run and pass. They just took what we gave him. They were hitting 4 yards here, 8 yards there, 12 yards there, and like I said, they kept the ball out of our offense's hands." -- Defensive tackle Terrance Knighton, on Chargers quarterback Philip Rivers and the San Diego offense.
What we learned about the Chargers
1. Despite uneven play that included a three-game losing streak in early November, the Chargers are showing signs lately that they are a playoff-worthy team. The 27-20 upset of high-powered Denver was San Diego's third win in four games. The Chargers also own wins over the Kansas City Chiefs and Indianapolis Colts, both playoff-caliber teams.
"We know we need help," Chargers quarterback Philip Rivers said. "We obviously know we've got to win the next two and need some help, but we've just got to keep it one game at a time and enjoy the heck out of the turn we've made and see if we can keep it going."
2. Wide receiver Keenan Allen, the Chargers' third-round draft pick, is staking a claim on Offensive Rookie of the Year. He scored four touchdowns on his past five catches, including two scores Thursday. His 63 receptions on the season lead all NFL rookies. Allen is becoming the go-receiver for Rivers.
"I don't know that there's another rookie receiver playing better than he is or has the numbers he has," Rivers said. "He just has the knack for playing. It's not too big for him. He has the swagger and the confidence you want in a wide receiver, but yet the eagerness and the humbleness to know, 'I'm a rookie and I've got to learn a lot and I want to learn a lot.' And then he just makes plays."
What we learned about the Broncos
1. Lost in the attention paid to the Broncos' high-powered offense is the vulnerability of the Denver defense. The Broncos gave up 114 points the past four games, an average of 28.5. They lost two of those games, stalling their march toward the AFC's top playoff seed. Some key injuries, especially in the secondary, affected the Broncos, but the team must find a way to tighten up on defense to ease the pressure on the offense, especially if Denver finds itself in a tight, defense-oriented game, as happens so often in the playoffs.
2. The Broncos found out just how important Wes Welker is to their offense. Welker missed the game after suffering his second concussion in four weeks, and the Broncos missed his play-making presence as a slot receiver. Denver leans on Welker, especially on third down, and it was no coincidence that the offense struggled to move the ball in his absence. In the second quarter, the Broncos didn't make a first down, and they finished the quarter with three consecutive three-and-outs.
"Players need to step up and make plays, and we will," Broncos running back Montee Ball vowed.