The 49ers forced three turnovers, leading to two short touchdown drives and a defensive score, and they sacked Sam Darnold four times in the first half. The visitors lead the Seahawks 21-13 at halftime.
The 49ers, though, will have to play the rest of the game without linebacker Dre Greenlaw, who was ejected with 6:04 remaining in the second quarter. Greenlaw chased Darnold out of bounds and then headbutted a helmetless Seahawks linebacker Ernest Jones IV on the sideline.
The 49ers had a four-play, 18-yard touchdown drive after Renardo Green’s interception of Darnold on third down on a pass intended for Jaxon Smith-Njigba. Mike Evans scored on a 2-yard reception.
They had a one-play, 11-yard drive after Fred Warner forced a fumble by Seahawks running back Emanuel Wilson and Malik Mustapha recovered. Christian McCaffrey scored on the next play.
The Seahawks’ third turnover, a fumble by running back George Holani, was forced by rookie Gracen Halton and recovered in the end zone by Halton with 13 seconds left in the half. Coach Mike Macdonald will face a postgame question about why he didn’t take a knee, though the 49ers had all their timeouts.
The Seahawks’ touchdown came on only a 24-yard drive after Jacob Cowing muffed a punt that Eric Saubert recovered. Wilson scored on a 2-yard run.
The Seahawks also had field goals of 49 and 50 yards from Jason Myers.
The 49ers outgained the Seahawks 112 to 110 in a defensive battle with seven punts, five by San Francisco.
Brock Purdy is 8-of-14 for 81 yards and a touchdown, with Evans catching three for 38 and a touchdown. McCaffrey has six carries for 34 yards and a touchdown.
Darnold is 8-of-14 for 79 yards with an interception, and Smith-Njigba has two catches for 42 yards. Wilson has 11 carries for 29 yards and a touchdown.