SEATTLE -- The Seattle Seahawks finally put everything together to get their first complete win of the season Sunday, beating the San Francisco 49ers 37-18 in a game that was never in doubt, but afterward there was still one big question regarding the Seahawks' immediate future.

Star quarterback Russell Wilson sprained his left knee in the win, and while coach Pete Carroll expects him to play next week, it's likely Wilson will be less than 100 percent.

"A little bit of a knee sprain," Carroll said late Sunday afternoon, less than an hour after the game. "He's walking around feeling good about it. He's half-crazy about these things. He's going to will it to happen; that's just the way he is. But most likely, he's going to be fine."

Wilson's injury was about the only thing that went wrong for the Seahawks on an afternoon when Seattle (2-1) was in control from the opening minute.

"We just executed at our level," wide receiver Doug Baldwin said after the Seahawks piled up 415 yards of offense.

Running back Christine Michael rushed for 106 yards and his first two career touchdowns, and tight end Jimmy Graham added his first score in nearly a year, as the Seahawks jumped out to a big early lead and never looked back.

San Francisco (1-2) had most of its 254 yards during the meaningless fourth quarter. The 49ers went 0-for-6 on third downs in the first half, falling into a 24-3 hole after 30 minutes.

"We knew going against as talented a team as there is in football today, our job was to convert on third downs," 49ers coach Chip Kelly said, "and we didn't do that."

San Francisco running back Carlos Hyde rushed 21 times for 103 yards and two fourth-quarter touchdowns in the loss.

Wilson completed 15 of 23 passes for 243 yards and a touchdown and survived a scary tackle five minutes into the second half that left him writhing in pain on the turf. Wilson went down hard on a horse-collar tackle from San Francisco linebacker Eli Harold and had to come out for one play. He favored his left knee for the rest of the drive and backup Trevone Boykin took over for good late in the third quarter.

"I was fortunate," Wilson said after the game. "I don't think it was as severe as it looked, thank God. I think I'll be all right."

Boykin, an undrafted rookie from Texas Christian University, completed 7 of 9 passes for 65 yards and a touchdown but also threw an interception in his first regular-season action. He connected with Doug Baldwin for a 16-yard touchdown early in the fourth quarter, giving the Seahawks a 37-3 lead with 12:53 remaining.

Baldwin caught eight passes for 164 yards and the score. Graham, who is coming back from knee surgery, had six receptions for 100 yards and a touchdown as Seattle piled up 308 receiving yards.

Seattle kicker Steven Hauschka made all four of his field-goal attempts and is 7-for-7 on the season.

San Francisco's first touchdown came on Hyde's 8-yard run with 7:50 remaining, pulling the 49ers to within 37-10. Hyde added a second 8-yard touchdown with 56 seconds left, while quarterback Blaine Gabbert had 119 yards on 14-for-19 passing. He also threw an interception, the Seahawks' first takeaway of the season.

"I thought he played OK," said Kelly, who added that he never considered turning to backup Colin Kaepernick in the blowout loss.

Two Michael touchdown runs helped the Seahawks jump out to a 14-0 first-quarter lead on the way to a 24-3 advantage at halftime.

Michael broke a 41-yard touchdown run on his first carry of the game as the Seahawks took a 7-0 lead just 43 seconds into the game. Baldwin caught a 34-yard pass on the second offensive snap, then Michael scored his first career touchdown on the Seahawks' third play.

Michael struck again on Seattle's second offensive series, scoring from 4 yards out to cap off a 14-play, 62-yard drive. His second touchdown of the day gave the Seahawks a 14-0 lead with 4:08 remaining in the first quarter.

After San Francisco finally got on the board with a Phil Dawson field goal, Graham caught his first touchdown pass since Sept. 27, 2015, to open up a 21-3 Seattle lead. Graham's 18-yard reception from Wilson came with 7:53 remaining in the first half.

A little over six minutes later, Hauschka added a 33-yard field goal to put Seattle ahead 24-3 heading into halftime.

Hauschka added three more field goals in the second half.

NOTES: RB Thomas Rawls was among Seattle's inactives. Rawls bruised his shin in the Week 2 loss to the Rams, but the Seahawks were holding out hope that he might be available against San Francisco. ... 49ers QB Colin Kaepernick knelt during the national anthem once again Sunday, when he was joined by teammates Eric Reid and Eli Harold. ... 49ers TE Vance McDonald hurt his hip in the second quarter and did not return. McDonald had three of San Francisco's six pass receptions when he got hurt. ... San Francisco also lost starting CB Jimmie Ward, who suffered a quadriceps injury in the second quarter and was out for the rest of the game. ... 49ers WR Torrey Smith (ankle) and TE Garrett Celek (back) were both hurt in the game but were able to return. ... San Francisco's Chip Kelly and Seattle's Pete Carroll were meeting for the third time as head coaches. Kelly's University of Oregon football team beat Carroll once when he was coaching at USC, and Carroll and the Seahawks beat Kelly's Philadelphia Eagles 24-14 in 2014.