SAN DIEGO -- Not even Norvstradamus could have seen this coming.

With four straight wins, the San Diego Chargers seemed poised for another strong dash to the finish line under Norv Turner. Their offense had been churning and their defense was swarming.

With two straight losses, the Oakland Raiders appeared headed back toward oblivion, where they've been since getting humiliated by Tampa Bay in the Super Bowl here in January 2003.

Then the Raiders shocked San Diego 28-13 on Sunday, putting a serious crimp in the playoff hopes for the four-time defending AFC West champion Chargers.

Jason Campbell ran for one touchdown and threw for another, and Oakland's running game, which had been stopped cold in consecutive losses, piled up 251 yards. Darren McFadden ran for 97 yards and a TD, and Michael Bush ran for 95 yards and a score.

It helped that the Raiders (6-6) were staked to a 14-0 lead thanks to two Chargers turnovers in the first quarter.

San Diego, which had gotten two straight 100-yard games from Mike Tolbert, had just 21 yards rushing, tied for seventh-lowest in team history. Tolbert had only 16 yards on seven carries. Rookie Ryan Mathews didn't play, apparently still bothered by a high ankle sprain.

CBSSports.com Grades
Oakland Raiders
A-	Jason Campbell was not spectacular but he avoided any big mistakes. Campbell was aided by a decent rushing attack against a team that came into the game with the third ranked rush defense. If this Raiders team shows up for the rest of the season they could be fighting for a playoff spot.
San Diego Chargers
F	Everything that the team had done well during their four-game win streak vanished against the Raiders. Good special teams play disappeared. Great pass protection was nowhere to be found. The NFL's third ranked rushing defense never showed up. The secondary, who had intercepted QB Peyton Manning four times a week ago, could not find one of QB Jason Campbell's passes.
By Dan McLellan RapidReports Correspondent Give us your grades on Twitter

The Raiders swept the season series for the first time since 2001.

"I think it's just really about getting back to who we are and what we do," coach Tom Cable said.

"Everyone was talking all week long about the hottest team in football and on and on," Raiders defensive tackle Richard Seymour said. "We give them a lot of credit. They are a good football team, but we just understand what we need to in order to beat these guys. And we give a lot of credit to the offensive line. We just wanted to run it at them."

The Chargers (6-6) are tied with Oakland for second in the division, two games behind the Kansas City Chiefs with four to play. If the Chargers lose to the Chiefs in San Diego next Sunday, their playoff chances would be all but finished. Kansas City surprised San Diego 21-14 on opening night and would hold the big tiebreakers if it beats the Chargers again.

"It's obviously very disappointing we weren't able to play at the level we've been playing over the last month." Turner said.

The Chargers' streak of 18 straight December victories -- which tied an NFL record for most victories in any month- - came to a thudding end. Their last December loss was on Dec. 31, 2005. San Diego had been tied with the 1970-74 Miami Dolphins, who won 18 straight in Novembers.

The Raiders beat the Chargers 35-27 at Oakland on Oct. 10 when consecutive blocked punts early in the game led to a touchdown and a safety. That victory snapped Oakland's 13-game losing streak to the Chargers.

The Chargers corrected their problems during a four-game winning streak, but then reverted to the form that showed during an ugly 2-5 start.

Darren Sproles fumbled a punt early in the first quarter and Hiram Eugene recovered at the San Diego 18. On fourth-and-1 from the 9, the Raiders fooled the Chargers with a fake up the middle by fullback Marcel Reece while Campbell ran a naked bootleg to the left for an easy touchdown.

"Watching Cam Newton at Auburn, I had to go back to my Auburn days and make some plays with my feet," Campbell said. "That's something that helps our team when I'm able to do things like that and put pressure on the defense."

On the next Chargers possession, Philip Rivers overthrew Malcom Floyd and the ball went right to safety Michael Huff, who returned it 15 yards to the San Diego 41. Campbell completed the drive with a 4-yard TD pass to rookie Jacoby Ford in the right corner of the end zone for a 14-0 lead.

After San Diego's Nate Kaeding kicked a 39-yard field goal, Campbell led an 80-yard, 11-play drive that was capped by Bush's 7-yard TD run, when he used a spin move and a strong second effort to power into the end zone for a 21-3 lead.

Campbell was back at quarterback after Bruce Gradkowski was hurt late in the fourth quarter of last Sunday's 33-17 loss to Miami, which led the Raiders to put him on injured reserve, ending his season.

The Chargers cut the gap to 21-13 on a 33-yard field goal by Kaeding in the third quarter and Rivers' 4-yard scoring pass to wide-open Antonio Gates with 9:59 left.

Campbell then led a drive capped by McFadden's 7-yard run with 4:35 left.

Campbell outgained the Chargers' running game all by himself, with 37 yards on seven carries.

"It's disappointing," said Rivers, who threw for 280 yards and was sacked four times. "I didn't make some throws. I didn't play as well as I needed to. I didn't play winning football."

Notes

• It was only the second time in their history the Chargers had no first downs rushing.
• The Raiders had 13 penalties for 105 yards.
• Sproles sustained a concussion when he was hit by Oakland's Rolando McClain just before halftime.
• Chargers WR Legedu Naanee aggravated an injured hamstring.
• The Chargers had a season-low 286 yards in total offense.