The Raiders kept their slim playoff hopes alive and ended years of frustration against their most bitter rival.
Jeff Hostetler threw three touchdown passes, Napoleon Kaufman ran for 109 yards and Oakland held Kansas City to 71 passing yards in a 26-7 victory on a rainy Monday night.
Kansas City dominated the rivalry in recent years, winning seven straight and 13 of their previous 14 games against the Raiders, including a playoff game in 1991.
Rich Gannon, who replaced Steve Bono as Kansas City's starting quarterback two games ago, was just 12-of-33 for 88 yards and was called for a safety on an intentional grounding penalty in the end zone. Gannon threw a 12-yard scoring pass to Sean LaChapelle in the fourth period.
Hostetler, who was 13-of-27 for 150 yards, had scoring passes of 34 yards to Tim Brown, 23 yards to Derrick Fenner and 1 yard to Andrew Glover. Cole Ford added a 43-yard field goal.
The Raiders have given up just 14 points in their past two games. They defeated Miami 17-7 a week ago in Oakland.
Defensive tackle Chester McGlockton had another dominating game for Oakland, forcing the safety and sacking Gannon twice. He also caused havoc in the backfield throughout the game.
The Raiders held the Chiefs to 13 yards passing in the first half while using several big plays to build a 10-0 lead.
Brown, who last week set an NFL record for career punt returns, returned a punt 36 yards to the Kansas City 46 to set up Oakland's first score.
Kaufman avoided two tacklers while scampering 45 yards on the next play, and Glover caught his touchdown from a scrambling Hostetler two plays after that.
On Kansas City's next possession, Gannon overthrew LaChapelle and safety Darren Carrington intercepted and returned it 21 yards to the Chiefs 29. The Raiders gained just 4 yards, but Ford kicked a line-drive field goal that barely cleared the crossbar with 3:47 left in the first period.
The Chiefs came unglued at the start of the second half.
Tamarick Vanover started to return the kickoff, then stopped and tried to down the ball for a touchback. But he put his hand down beyond the goal line and, after hesitating for a few seconds, realized he had to keep going. He was tackled at the 10.
On the next play, Gannon was hit by Pat Swilling and then McGlockton in the end zone and was flagged for intentional grounding when, while falling backward, he underhanded the ball to an empty field at the 3.
The Chiefs backed Oakland up to its 2 midway through the third period, but Tony Stargell was called for a 31-yard pass interference call on a third-and-7, and Kaufman sprinted 34 yards around the corner on the next play.
Three plays later, Hostetler lofted a pass to Fenner for the touchdown, which completed a 98-yard drive.
After Kansas City was forced to punt, Hostetler made it 26-0 with his scoring pass to Brown late in the third quarter.
The Chiefs finally scored 37 seconds into the final period on LaChapelle's scoring catch.