SAN DIEGO » It was such a bad day for the San Diego Chargers that even their cheerleaders were booed by Oakland Raiders fans who had Qualcomm Stadium all to themselves after the local fans bolted in the fourth quarter.

A 28-13 beatdown Sunday by the hated Raiders — who shredded San Diego’s defense for 251 yards rushing — left the Chargers’ playoff hopes bruised and bloodied.

The Chargers need to win out and get some help from other teams to win their fifth straight AFC West title after they were outmuscled by the Raiders on both sides of the ball.

The Chargers are tied with Oakland at 6-6, two games behind Kansas City (8-4) with four to play. The Chargers host the Chiefs on Sunday, needing a win to remain in contention. The Chiefs beat the Chargers 21-14 on opening night.

"I think the disappointment ought to eat at you here for a little while longer, then you’ve got to shift gears quickly to Kansas City," quarterback Philip Rivers said yesterday. "We are still alive. Again, is it best-case scenario? No, but we’ve put ourselves in that by this game yesterday and games in September and October to where you don’t have any wiggle room."

Besides trying to reel in the Chiefs, the Chargers need to be concerned about the Raiders. Oakland doesn’t have room for error, either, but it swept the Chargers for the first time since 2001, so it holds the tiebreaker. Oakland plays at Kansas City on Jan. 2, the final day of the regular season.

After hosting the Chiefs, the Chargers host the San Francisco 49ers four days later, then finish with games at Cincinnati and at Denver. The Chargers are 1-3 in the division, while Oakland is 4-0 and Kansas City is 2-2.

The Chargers had won four straight, including what they termed as their most complete game, a 36-14 victory at Indianapolis in which they intercepted Peyton Manning four times.

But against the Raiders, they looked more like the bumbling Bolts who staggered to a 2-5 start due to special teams blunders and turnovers. A fumbled punt by Darren Sproles and an interception by Rivers helped spot the Raiders a quick 14-0 lead.

"We didn’t play our best game," Rivers said. "I would imagine numerous guys in that locker room would say individually that they didn’t play their best. I know I didn’t. As a whole, we didn’t. Oakland had a lot to do with it. They outplayed us. It certainly wasn’t just our lack of execution. It was a combination. And they had something to do with our lack of execution, certainly.

"They played a great game and they whipped us."

While Darren McFadden ran for 97 yards and a TD, and Michael Bush ran for 95 yards and a score, Oakland stopped San Diego’s running game.

San Diego had 21 yards rushing, tied for seventh-lowest in team history.