OAKLAND, Calif. -- Derek Carr wouldn't mind having a stress-free fourth quarter sometime this season.

For now, though, the Oakland Raiders quarterback is enjoying the team's nail-biting, single-digit wins.

Carr passed for 317 yards and two touchdowns, and the Raiders held on for a 34-31 victory against the San Diego Chargers on Sunday at the Oakland Coliseum.

Oakland improved to 4-1, with all four wins coming by seven or fewer points, two of them by a single point.

"This league is designed for everybody to go 8-8," Carr said. "It really is. It's that close in talent and coaching in everything. Sometimes you just have to find ways to win and get it done at the end. It would be nice if we didn't have to do all the stress and drama at the end. That would be nice."

Carr completed 25 of 40 passes with one interception, and Amari Cooper made six receptions for 138 yards and a score as the Raiders moved into a first-place tie in the AFC West with the Denver Broncos, who lost 23-16 to the Atlanta Falcons.

"It's nice, but the road still goes through Denver," Carr said. "They are Super Bowl champs, division champs. I will always pay respect to them because that's what they've earned. We have earned absolutely nothing yet. We've earned four wins in five games, which is a great feeling. It feels very nice, trust me, but we haven't done anything yet."

The Raiders are 4-1 for this first time since 2002, which is the last season they reached the Super Bowl and last time they made the playoffs.

San Diego (1-4) lost its third straight game and fell for the 10th consecutive time against teams from the AFC West. The Chargers blew fourth-quarter leads in their first three losses. This time they wasted a chance to pull even with just over two minutes left.

With the Raiders leading 34-31, San Diego's Josh Lambo lined up to kick a 36-yard field goal. However, holder Drew Kaser -- the punter -- fumbled the ball when he tried to place it for Lambo, and the Raiders took over at the Chargers 35-yard line with two minutes remaining.

"Just when you think you've seen it all, something like that happens," San Diego coach Mike McCoy said. "Too many turnovers throughout the game and critical mistakes at critical times once again."

Chargers quarterback Philip Rivers completed 21 of 30 passes for 359 yards and four touchdowns with two interceptions. He has 292 career touchdown passes, moving him past Johnny Unitas (290) and Warren Moon (291) into ninth place on the NFL's all-time list.

Rivers, however, wasn't in a mood to celebrate after what happened late in the fourth quarter.

"You can't make this stuff up," Rivers said. "You think, 'Is there any other way we can find a way to do this?' Obviously, that (field goal) wasn't going to win the game for us, but it was going to get us right there, and who knows?"

Kaser said he didn't know what went wrong on the botched hold or his 16-yard shanked punt on the last play of the third quarter that gave Oakland the ball at San Diego's 32. Fullback Jamize Olawale blasted into the end zone for a 1-yard touchdown as the Raiders increased their lead to 34-24 with 12:51 to play.

Raiders wide receiver Michael Crabtree caught three passes for 47 yards and a touchdown, giving him five TD grabs on the season. Cooper had his first touchdown catch of the season.

Wide receiver Tyrell Williams caught five passes for 117 yards and a touchdown, and Travis Benjamin had seven catches for 117 yards for the Chargers. Tight end Hunter Henry caught three passes for 74 yards and a score, and tight end Antonio Gates (hamstring) returned from a two-game absence and had four catches for 30 yards and a TD.

"We gave up way too much today," Raiders defensive end Khalil Mack said. "We got to look at it and correct. We got some new guys back in coverage and we got some new guys up front. We got to mix it in and hold it down for the offense."

Chargers rookie defensive end Joey Bosa, the No. 3 pick in this year's draft, made his debut after sitting out the first four games with a hamstring injury. He recorded his first two career sacks and finished with five tackles.

"There's been no give up," McCoy said. "There will be no give up here. Our guys play their hearts out every week."

NOTES: Raiders rookie RB DeAndre Washington made his first career start, replacing Latavius Murray (toe), who was inactive. He rushed for 29 yards on nine carries and caught five passes for 29. ... Chargers backup ILB Korey Toomer, who was on the Raiders' practice squad earlier this season, started in place of Denzel Perryman (shoulder). ... Oakland TE Mychal Rivera made his first start of the season, replacing Clive Walford (knee). ... San Diego CB Casey Hayward made his second straight start in place of Brandon Flowers (concussion). ... Chargers CB Craig Mager started in place of Jason Verrett, who was placed on injured reserve Friday due to a torn knee ligament. ... Raiders OLB Perry Riley, who was signed earlier in the week as a free agent, made his debut, starting in place of Malcolm Smith (quad). Riley had a team-high seven tackles and forced a fumble.