The Seattle Seahawks defeated the Kansas City Chiefs 20-3 on Sunday Night Football at Lumen Field, NBC News and The Seattle Times reported. Seattle's defense held Patrick Mahomes to 165 passing yards and smothered Kenneth Walker III, the Super Bowl MVP now with Kansas City, to his lowest rushing total of the season.

NBC News said the Chiefs' three points tied their lowest output in any Mahomes start, and Kansas City posted its fewest total yards, first downs, and red-zone drives in a Mahomes start, per NFL researcher Tony Holzman-Escareno. Linebacker Derick Hall forced a Mahomes fumble. Receiver Jaxon Smith-Njigba had a big first half, The Seattle Times reported.

After two straight losses, Seattle moved within two games of the San Francisco 49ers in the NFC West. Coach Mike Macdonald praised the defensive effort. Chiefs coach Andy Reid said the offense would go back to the drawing board.

Mahomes entered as one of the league's top dual threats. Walker had run for at least 115 yards in four of Kansas City's first five games before Sunday's collapse against Seattle's front.

Seattle needed a statement after two straight losses in a tough NFC West. Kansas City entered as the league's last unbeaten team and left with a rare low-scoring night. Special teams and the run game both leaned Seattle's way.

The crowd at Lumen Field stayed loud all night. Seattle's front seven won most downs. Kansas City must fix a stalled offense.

Seattle climbs in the NFC West race.

What we know: Seattle won 20-3 and held Mahomes to 165 yards. Kansas City took its first loss.
What we don't: How either team adjusts next week, and injury updates beyond the box score.