SAN DIEGO — They didn’t take the easy road, but the San Diego Chargers woke up Monday on top of the American Football Conference and, of course, the AFC West.

The Chargers disposed of the Oakland Raiders in a 31-28 thriller on Sunday. It was not the cleanest of wins, but sometimes one has to get some dirt under the nails to prevail in Oakland.

That’s just what the Chargers did in reeling off their fifth straight victory and gaining their second road win in three outings.

No team in the AFC can match the Chargers’ 5-1 mark. Maybe few can match their grit either.

“We were in a dog fight from the get-go,” said cornerback Jason Verrett, whose interception iced the triumph over the Raiders.

The Chargers, at times, looked more like the Raiders (0-5). There was some sloppy play, inopportune penalties and a series of mistakes — by players and coaches — that seemed uncharacteristic for this year’s squad.

“It was outstanding for our football team to fight through some adversity,” coach Mike McCoy said.

In the end, quarterback Philip Rivers was the difference. Rivers threw for two touchdowns and had another stellar game as the team won the first of its three games in 11 days against AFC West foes.

“They talk about finishing,” Verrett said, a rookie. “It definitely rubs off on the younger guys.”

The rub from Sunday’s outing is that the Chargers don’t have to play their best to beat a winless team.

But the uneven performance also could serve as a red flag that the Chargers need to tighten their game before wrestling with the visiting Kansas City Chiefs on Sunday and the Denver Broncos the following Thursday.

Rivers is playing at an MVP level, but he could be even better with the running game beginning to showing up.

Running back Branden Oliver is starting to be noticed by the rest of the NFL after two straight solid games as he has helped resurrect the Chargers’ running game.

Oliver has taken on more of a load with Ryan Mathews out with a sprained knee and Danny Woodhead out for the season with a broken leg.

Oliver, a Darren Sproles look-alike who is an undrafted rookie, has heard appreciative comments from teammates.

“It feels great to hear the veterans talk like that, but I still have a lot of work to do,” Oliver said. “You’ve got to keep your body right because it’s like two football seasons. I’m a little sore but nothing outrageous.”

NOTES: Cornerback Brandon Flowers left the game with a groin injury and Richard Marshall will replace him if necessary. … Wide receiver Eddie Royal didn’t return after suffering a rib injury. … Inside linebacker Manti Te’o is still out indefinitely with a foot injury. … Wide receiver Keenan Allen could see his role increase as punt returner.

REPORT CARD VS. RAIDERS

–PASSING OFFENSE: A — Philip Rivers’ play continues to be top-shelf as he set an NFL record with his fifth straight game with a passer rating of at least 120. He threw for two touchdowns and didn’t turn the ball over. More than that, he was the calm, steady hand as the Chargers mounted a late comeback. Rivers felt some pressure, but often negated it by stepping up into the pocket and keeping the play alive. Eddie Royal and Malcom Floyd continue to shine.

–RUSHING OFFENSE: A — Brandon Oliver has been a find, energizing the running attack. He had another solid game, scoring the winning TD with a 1-yard plunge. The run blocking picked up as the game wore on. Ronnie Brown was back in the mix and supplied Rivers with the confidence that the pass protection would be provided.

–PASS DEFENSE: C — Jason Verrett’s game-clinching interception can’t be overlooked. But neither can a rookie quarterback throwing for four touchdowns and leaving with a pristine uniform. The Chargers blew more coverages on Sunday than they had the previous three weeks and it almost cost them. What was obvious was the Raiders’ offensive line having its way with the Chargers’ pass rushers. Raiders QB Derek Carr was seldom pestered and never sacked.

–RUSH DEFENSE: C — The Raiders’ blockers opened holes and created creases for Darren McFadden and Maurice Jones-Drew. Often the Raiders’ backs were in the defense’s second level before a hand was laid on them. The Raiders broke the century mark and almost broke the Chargers’ hearts. If they would have stuck with the run in their final drive, they might have upset the Chargers. Donald Butler was OK at inside linebacker, and he was the best of the bunch. Not a fine day here.

–SPECIAL TEAMS: B — Allen was subbing for a banged-up Royal when he produced a 29-yard punt return in the fourth quarter that might have been the most important play of the game. The coverage units were fine. Nick Novak was good on his lone attempt; he had a 52-yarder erased on a holding penalty. Eric Weddle’s ill-advised pass on a fake punt was a black mark here.

–COACHING: B — Mike McCoy’s bunch seemed a step slow mentally and physically early in the game. But he chose to ride the hot hand of Oliver down the stretch for the win. That showed McCoy was adaptable in turning away from a proven passing game for a running game that suddenly has revealed a pulse. Defensively, John Pagano kept trying to create some sort of heat on Carr, and it just wasn’t there. The run defense was exposed as second-stringers continue to play more prominent roles. But the Chargers overcame all of that and won, and there’s nothing better to take home from a trip to Oakland.