Philip Rivers and the San Diego Chargers pulled off one of the biggest upsets of the NFL season, stunning Peyton Manning and the Denver Broncos 27-20.

The Broncos came into Thursday night's game at Sports Authority Field in Denver holding an AFC-leading 11-2 record and knowing they could clinch home-field advantage in the playoffs by winning their final three regular-season games.

But after racing out to a 10-3 lead in the first quarter, Denver was thoroughly outplayed by a more balanced Chargers team that now has its sights set on a possible playoff berth.

Rivers completed 12 of 20 pass attempts for 166 years and threw two touchdowns and no interceptions to rally the Chargers. Both of those TD passes came in the second quarter, as San Diego turned a seven-point deficit into a 17-10 lead at halftime.

The Chargers, who rushed for 177 yards compared to a measly 18 for the Broncos, stretched their lead to 24-10 when Ryan Matthews scampered for a 23-year TD run early in the second half.

Manning, who finished with 289 passing yards, two touchdowns and one interception, tried to pull off some late-game heroics, connecting with Andre Caldwell on a five-yard TD pass near the start of the fourth quarter.

But the Chargers' Nick Novak effectively sealed the victory when he connected on a 35-yard field goal with just over 2:30 remaining in regulation.

The loss jeopardizes the Broncos' bid to clinch the top seed in the AFC and home-field advantage in the playoffs.

If the New England Patriots and Kansas City Chiefs both win on Sunday, they will equal the Broncos' 11-3 record heading into the final two games of the season.

The Chargers are trying to beat out the Miami Dolphins and Baltimore Ravens, who both have 7-6 records, for the second AFC wildcard berth.

The New York Jets (6-7) are also still in the playoff picture in the AFC. EFE