SANTA CLARA, Calif. — In a gripping encounter, Zach Charbonnet’s explosive 27-yard touchdown run in the first quarter set the tone for Seattle, as they stifled San Francisco’s formidable offense to secure a 13-3 win on Saturday night. This victory clinched the top seed for the Seahawks in the NFC playoffs.

With a stellar 14-3 record, Seattle claimed its first division crown since 2020. Now, they are just two home victories away from potentially returning to Levi’s Stadium for next month’s Super Bowl, having outmaneuvered San Francisco (12-5) in a rare, high-stakes season finale where the winner was assured the coveted No. 1 playoff seed.

The defeat pushes the 49ers into the wild-card round, sending them on the road next weekend to face a yet-to-be-determined opponent, which will be decided after Sunday’s matchups.

Under the leadership of Coach Mike Macdonald, Seattle’s defense confounded a 49ers offensive squad that had been the NFL’s most dynamic since Brock Purdy’s return from injury in Week 11.

Seattle’s defense was relentless, not allowing a single first down in the first quarter, racking up three sacks, and making a pivotal defensive play early in the fourth quarter. Drake Thomas intercepted a pass at Seattle’s 3-yard line after it deflected off the hands of Christian McCaffrey.

Sam Darnold managed the game efficiently for the Seahawks, redeeming himself in this critical Week 18 matchup. Unlike last year, when a loss to Detroit cost Minnesota the top seed, Darnold rose to the occasion, playing a key role in securing Seattle’s victory.

Darnold went 20 of 26 for 198 yards and didn’t turn the ball over once as Seattle relied heavily on the running game.

Kenneth Walker III ran for 97 yards, Charbonnet had the long TD and the Seahawks finished with 180 yards on the ground, their second most in a game this season.

Purdy went 19 of 27 for 127 yards and the interception and McCaffrey was held to 23 yards on eight carries as the 49ers had their lowest-scoring game since losing 23-3 to Carolina in coach Kyle Shanahan’s debut in 2017.

The 173 yards gained by the 49ers were their fewest in any regular-season game under Shanahan.

The Seahawks controlled the first half, outgaining the 49ers by 127 yards and allowing only three first downs, but led only 10-3 at the break after two long drives ended with no punts.

Seattle got stopped on fourth-and-goal from the 4 on the on the opening drive but managed to force a three-and-out that set up a short field and Charbonnet’s TD run.

Jason Myers also missed a 47-yard field goal attempt. He went 2 of 4 on the night, missing from 26 yards late in the fourth quarter.