Christian McCaffrey rushed for 114 yards and two touchdowns as the San Francisco 49ers defeated the host Seattle Seahawks 31-13 Thursday night.

Wide receiver Deebo Samuel also rushed for a score for the 49ers (8-3), who built a two-game lead over the Seahawks (6-4) atop the NFC West. Samuel also had a game-high seven catches for 79 yards.

San Francisco quarterback Brock Purdy completed 21 of 30 passes for 209 yards with one touchdown -- a clinching 28-yarder to Brandon Aiyuk with 7:51 remaining -- and one interception.

Seattle's Geno Smith was 18 of 27 for 180 yards with no touchdowns and one interception. The 49ers had a season-high six sacks. With Kenneth Walker III out due to an oblique injury, rookie running back Zach Charbonnet led the Seahawks with 47 yards rushing on 14 carries and had a team-high four receptions (for 11 yards).

The 49ers dominated the first half while taking a 24-3 lead.

Samuel capped the game's opening possession, a nine-play, 71-yard march, by scoring untouched on a 2-yard run.

Seattle's Dee Eskridge returned the ensuing kickoff 66 yards, but the Seahawks managed just 1 yard before settling for Jason Myers' 51-yard field goal.

McCaffrey scored from 1 yard out early in the second quarter and then dragged several defenders over the goal line on an 8-yard run with 5:11 left in the half.

Jake Moody kicked a 32-yard field goal with 39 seconds left before the break after Seattle's DeeJay Dallas muffed a punt.

The Seahawks had just one first down and 11 yards of total offense before Smith drove them into field-goal range in the closing seconds of the half. However, Myers' 53-yard attempt faded just right.

Seattle got a boost from its defense early in the third quarter as Jordyn Brooks intercepted a tipped pass and returned it 12 yards for a touchdown.

Myers added a 30-yard field goal on the Seahawks' next drive to make it 24-13, but Seattle couldn't get any closer.

--Field Level Media