ENGLEWOOD, Colo. (AP) — It didn't matter which quarterback the Denver Broncos had under center Sunday. The San Diego Chargers bottled up both the rusty Chris Simms and the hobbled Kyle Orton.

Philip Rivers and a dominant defense led the Chargers into sole possession of first place in the AFC West with a 32-3 drubbing of the Denver Broncos, who couldn't move the ball effectively behind either QB.

The Chargers (7-3) have won five straight and the Broncos (6-4) have dropped four in a row, turning the division race upside-down. Just five weeks ago, the Chargers trailed the Broncos by 3½ games.

The balance of power in the AFC West couldn't have shifted in a more dramatic fashion.

Rivers was a crisp 17 for 22 and he led San Diego to scores on seven of 10 drives. Nate Kaeding kicked four field goals and the Chargers also recovered an onside kick, recorded three sacks and forced three turnovers.

The Broncos? They were flagged nine times to San Diego's one. And Marcus Thomas blocked an extra point in the final minute.

Otherwise, all San Diego.

Simms' first start since nearly being killed in a game three years ago didn't last long. After getting sacked twice and losing a fumble, he was replaced by Orton, who didn't take a single snap in practice last week because of a sprained ankle.

Simms was just 2 for 4 for 10 yards with two sacks over three series. He handed the ball off the first half dozen times he took the snap but when he dropped back for his first pass at the Chargers 17, he was sacked by linebacker Shaun Phillips, who blew past backup right tackle Tyler Polumbus and raked the ball out of Simms' left hand.

Safety Steve Gregory recovered, and the Chargers drove downfield for a touchdown and never looked back.

On Denver's next possession, the Broncos were flagged twice and Simms was sacked again. Their third drive was thwarted by a holding call on left tackle Ryan Clady.

Legedu Naanee's 2-yard TD catch from Rivers and field goals of 28 and 47 yards by Kaeding made it 13-0 and Denver coach Josh McDaniels summoned Orton from the sideline.

Orton entered to a standing ovation that only grew louder when he quickly drove the Broncos 60 yards on three completions. But on first-and-goal at the 4, rookie running back Knowshon Moreno fumbled away the ball — and the game — at the goal line when left guard Russ Hochstein, slipped while leading the way, his left knee apparently jarring the ball loose.

While the Chargers celebrated safety Steve Gregory's recovery in the end zone, the Broncos let their frustrations get the better of them. Wide receiver Brandon Marshall got in Moreno's face and was jawing at the inconsistent rookie, and Moreno responded with a two-handed shove and Marshall was pulled away.

The Broncos got the ball back with 24 seconds left in the half and Orton threw an interception to Antonio Cromartie.

Orton, who finished 15 of 29 for 171 yards, wasn't any more effective after halftime. On Denver's first drive, he threw an incompletion on third down at the San Diego 5 in which linebacker Shawne Merriman went after his injured leg. Orton gingerly left the field but stayed in the game.

After Matt Prater's short field goal made it 13-3, the Broncos went for the onside kick but the ball went through Josh Barrett's hands and Naanee recovered for San Diego, leading to Tomlinson's 1-yard TD run and a 20-3 lead.

Orton had a dismal passer rating of 55.4 and Simms' was 56.2. Combined, they were about what Rivers was at 109.1.

Simms last started on Sept. 24, 2006, when he played for the Tampa Bay Buccaneers and was battered so badly by the Carolina Panthers that he needed emergency surgery to remove his spleen.