SEATTLE – An NFC West prize fight broke out here Sunday, complete with touchdowns, turnovers, taunting, tie scores and tense trading of leads.

Once this Week 5 doozy ended, the 49ers’ undefeated start reached 5-0 via a 32-29 triumph over the defending Super Bowl champion Seattle Seahawks.

It took a midfield stand, of all strange things, to finish off a thrilling chapter of this rivalry. The Seahawks (3-2) saw their last-minute drive end once a replay review upheld a ruling that Cooper Kupp came up a yard shy of a first down on a fourth-and-10 catch.

Eddy Piñeiro’s 43-yard field goal scored the 49ers’ winning points after he waited out the two-minute warning. Thin on receivers with Deebo Samuel out with a hamstring injury, they reached go-ahead position late in the fourth quarter thanks mostly to Christian McCaffrey, with an assist to his understudy, Kaelon Black.

Five minutes before Piñeiro’s winning kick, Jason Myers tied the game on his fifth field goal of the day, a 40-yarder that followed Keion White’s third-down sack of Sam Darnold.

The 49ers had wrestled back the lead with 11 minutes to spare, once Brock Purdy completed a go-ahead touchdown pass to Brandin Cooks, followed by Purdy finding Mike Evans for a 2-point conversion grab and a 29-26 lead.

Despite surrendering 29 points, the 49ers’ defense had its moments, from creating four takeaways and five sacks to overcoming Dre Greenlaw’s ejection.

After playing their first road game since the season-opening win over the Rams in Australia, the 49ers will next play their first prime-time game since that opener. Next Monday night at home, they will face the Washington Commanders, who are 1-3-1 after tying the New York Giants Sunday.

The 49ers owned a 21-13 halftime lead after perhaps their most chaotic first half since a 2019 thriller in New Orleans.

The second half started in stunning fashion, too, as Renardo Green notched his second interception of the game off Darnold. That turnover, unlike those in the first half, yielded neither a touchdown nor any points, as Piñeiro missed a 52-yard field goal attempt wide left.

The 49ers’ lead got trimmed to 21-16 when Myers made his third field-goal attempt, this one from 43 midway through the third quarter.

Purdy’s first interception since the season opener’s first half in Australia was the 49ers’ second turnover of the game. It came on a third-down pass to Jacob Cowing, and that Nehemiah Pitchett pick would set up a go-ahead, 16-yard touchdown catch-and-run by the Seahawks’ Jaxon Smith-Njigba, who juked Fred Warner and Malik Mustapha in the open field to give Seattle a 23-21 lead 5:52 remaining.

49ers turnover No. 3 came when Deebo Samuel coughed up the ball on a third-quarter stumble toward the left sideline, after being tripped up by Drake Thomas; Samuel injured his right leg or hamstring en route to his first lost fumble since 2024. The Seahawks converted it into Jason Myers’ fourth field goal of the game, a 48-yarder for a 26-21 lead 3:02 until the fourth quarter.

All three 49ers touchdowns in the first half came after Seahawks turnovers, and the most stunning came when rookie defensive tackle Gracen Halton forced a George Holani fumble at the goal line and pounced on the loose ball to celebrate his first career touchdown.

Halton disengaged from center Jalen Sundell and swiped the ball free with his right hand. Seattle got pinned down there after a Corliss Waitman punt was downed at the 4-yard line by Ashtyn Davis, but only after Siran Neal’s touchback-saving tip from the 1.

Seattle’s second turnover came courtesy of Fred Warner. Down 10-7, Warner took matters into his own hands, punching the ball from Emmanuel Wilson’s grasp to create in a fumble that Malik Mustapha recovered at the Seattle 11-yard line. McCaffrey scored a go-ahead touchdown run on the next snap, zipping past left-side blocks from Connor Colby, Trent Williams and Evans.

But with that 14-10 lead in hand, things got out of hand with Greenlaw’s sideline shenanigans. He first delivered a shoulder-to-shoulder late hit on a Darnold scramble, and as Darnold careened into the bench, Greenlaw got swarmed by Seahawks and headbutted a helmet-less Ernest Jones Jr. to merit a disqualification.

Sacks by Halton and Osa Odighizuwa stalled that Seahawks drive and Myers’ 50-yard field goal cut the 49ers’ lead to 14-13 with 1:56 remaining in the first half.

Converting takeaways into touchdowns was the first-half theme when it came to scoring.

The Seahawks’ first turnover came when Renardo Green intercepted Darnold’s third-down pass on their initial possession. That set up Brock Purdy’s 2-yard touchdown pass to Evans, who had a third-down conversion catch the previous play.

The Seahawks answered once Cowing opted against a fair catch and muffed a punt at the 35. The ball went through Cowing’s hands a split second before he was drilled by Pritchett. Former 49ers tight end Eric Saubert emerged from a scrum with the ball, and the Seahawks scored the equalizer six snaps later on a 2-yard touchdown run by Emmanuel Wilson.

The 49ers, however, emerged from this chaotic game with a two-game lead in the NFC West.