SAN DIEGO — It's all but over for the star-studded San Diego Chargers, who were done in Sunday by a rookie quarterback, a rookie head coach and a former teammate.

Yes, Matt Ryan, Michael Turner and the surprising Atlanta Falcons are very much alive in the NFC playoff picture, thanks to their 22-16 win over the collapsing Chargers.

Ryan, the rookie from Boston College, threw two touchdown passes and Turner, the former understudy to LaDainian Tomlinson, ran for 120 yards against his former team.

The Chargers? A popular preseason pick to make it to the Super Bowl, they're on the precipice of a super collapse.

"We got our butts kicked — plain and simple," said Tomlinson, the two-time defending NFL rushing champion who was held to a season-low 24 yards on 14 carries.

The Chargers (4-8) are three games behind the Denver Broncos with four to play in the anemic AFC West. The Broncos got their third straight road win, 34-17 over the New York Jets.

San Diego underwhelmed again under coach Norv Turner, losing for the fifth time in six games. The Chargers gained a season-low 201 yards.

A season after reaching the AFC championship game, San Diego can finish no better than .500.

Tomlinson spoke to his teammates afterward.

"The message was, don't give up. A lot of people around the league probably think we are going to pack it in and give up. But we won't."

The Falcons (8-4) continued their big turnaround from a 4-12 season, winning for the fourth time in five games under rookie head coach Mike Smith. They remain one game behind Tampa Bay and Carolina in the NFC South.

"We tried hard not to win this game," said tight end Justin Peelle, a former Charger who caught an 18-yard TD pass from Ryan. "Our defense played unbelievable. A lot of the win really goes to them. To hold that explosive offense to what we did today was unbelievable."

Ryan completed 17 of 23 passes for 207 yards. Turner carried 31 times in his sixth 100-yard game of the season. He was allowed to leave San Diego as an unrestricted free agent after last season.

The Chargers may have stuffed Turner on fourth-and-goal from the 1 right before halftime, but the bruising back got the victory he was seeking.

"They were in my face," Turner said. "They were laughing, but it was cool.

"It was a physical game," Turner said. "I expect that every week, especially from those guys. I practiced with them and I know what they do, and they know what I can do."

Turner is among those who are surprised at the Chargers' collapse.

"They're struggling this year — and now it's a shock."

Atlanta won despite losing three fumbles, which led to all of San Diego's points.

"They fought through it the entire game," Smith said.

With the Falcons trying to add to a 15-7 lead in the third quarter, Ryan completed a pass to Brian Finneran, who turned upfield and was hit by Quentin Jammer and fumbled.

Safety Eric Weddle, who'd been called for a big pass interference penalty on the drive, scooped up the ball and raced 86 yards down the left sideline for a touchdown. Ryan shoved referee Mike Carey out of the way as he chased Weddle.

Atlanta challenged, but the play was upheld after replay. Philip Rivers' 2-point conversion pass to Malcom Floyd failed.

Ryan threw a 5-yard touchdown pass to wide-open Harry Douglas in the left corner of the end zone on the first play of the fourth quarter for a 22-13 lead.

Jamaal Anderson blocked a 43-yard field-goal attempt by Nate Kaeding early in the fourth quarter. After the Chargers got the ball back on Turner's fumble, Kaeding kicked a 28-yarder to pull the Chargers to 22-16.

The Chargers got a gift late in the first quarter when Douglas muffed a punt and Anthony Waters recovered at the 20-yard line. Three plays later, Tomlinson scored from the 3-yard line for a 7-3 lead, then tossed the ball high into the air in celebration.

Jason Elam kicked his second field goal, from 40 yards, before the Falcons went ahead 13-7 on an 18-yard TD catch by tight end Justin Peelle, who played with the Chargers from 2002-05.

San Diego started its next drive on the 8, and a false start and a 3-yard loss by Tomlinson put the ball on the 1. Rivers dropped back to pass under heavy pressure and was whistled for intentional grounding in the end zone for a safety, giving Atlanta a 15-7 lead.

Notes: Tomlinson scored his 136th career touchdown, tying him with Marshall Faulk for fifth place all time. ... Tomlinson had five catches, giving him 502 for his career. He is the fifth player to rush for more than 10,000 yards and have 500 receptions. ... Norv Turner is 73-95-1 in three stops as an NFL head coach, including 15-13 with San Diego. ... Atlanta's Roddy White had six catches for 112 yards, putting him over the 1,000-yard mark for the second straight season. ... Weddle set a team record with his 86-yard fumble return TD.