LOS ANGELES (AFP) — Baltimore quarterback Lamar Jackson threw two third-quarter touchdown passes and the Ravens defense dominated to beat the San Francisco 49ers, 33-19, in a battle of the National Football League's conference leaders.

In a game touted as a potential Super Bowl preview, the Ravens intercepted San Francisco quarterback Brock Purdy four times.

Ravens safety Kyle Hamilton, who said before the game he felt "a little disrespected" that Baltimore were branded the underdogs, had two of those interceptions as the team's defense set an early tone before Jackson took control.

Jackson had given up a safety when he tripped over an official in the end zone and was called for intentional grounding.

The 49ers then settled for a field goal before the Ravens scored 13 straight points.

Baltimore led, 16-12, at halftime, and Jackson stretched the lead with a touchdown pass to Nelson Agholor early in the third.

Purdy threw his fourth interception of the game on the next play and Jackson promptly followed up with a scoring pass to Zay Flowers.

Things got even worse for the 49ers when Purdy departed the game in the fourth quarter after a sack that left him with a stinger — nerve trouble that temporarily affects feeling and muscle control in the shoulder and arm.

Backup Sam Darnold connected with Ronnie Bell for a touchdown, but Marcus Williams intercepted a Darnold pass in the end zone late in the fourth to effectively seal the win.

Jackson connected on 23-of-35 passes for 252 yards and led the Ravens with 45 rushing yards.

The Ravens improved to 12-3, best in the AFC, while National Football Conference West winner San Francisco fell to 11-4 — tied the NFC with the Detroit Lions and Philadelphia Eagles, who beat the New York Giants, 33-25, earlier Monday.

The day's other game saw the Las Vegas Raiders defense produce two touchdowns in a matter of seconds to key a 20-14 upset at Kansas City that put the Chiefs' bid to lock up the American Football Conference West division title on hold.

With their own offense sputtering, the Raiders defense took full advantage of multiple miscues from the reigning Super Bowl champion Chiefs and quarterback Patrick Mahomes.

The Raiders trailed, 7-3, when defensive tackle Bilal Nichols recovered a fumble and ran eight yards for a touchdown with 4:55 left in the first half.

A two-point conversion attempt was unsuccessful, but on the first play from scrimmage on the Chiefs' ensuing possession, Raiders cornerback Jack Jones intercepted Mahomes and raced 33 yards for a touchdown that put the Raiders up 17-7 with 4:48 remaining before the break.

Las Vegas' dominant defensive performance also included four sacks of a visibly frustrated Mahomes.

Harrison Butker also missed a field goal attempt and the Chiefs twice failed to convert on fourth-down plays in the second half.

Mahomes completed 27 of 44 passes for 235 yards and the interception. Isiah Pacheco rushed for a touchdown but departed early with a concussion after losing his helmet and taking a knee from a teammate to the head.

At 9-6, the Chiefs can still clinch an eighth straight AFC West title with a victory over the Cincinnati Bengals next week.

"I still believe that we can go do what we want to do," Mahomes said after the sloppy performance.

"If we clean it up, we can beat anybody. I truly believe that, but we've got to prove that we can do it."

The Raiders improved to 7-8 to keep their playoff hopes alive.