Instant analysis of 49ers’ 20-17 home loss to Seahawks

SANTA CLARA – The 49ers collapsed in the fourth quarter earlier this season against the Los Angeles Rams and the Arizona Cardinals, and they completed the NFC West trifecta Sunday against the visiting Seattle Seahawks.

If the 49ers (5-5) fail to win a third straight division title, it will be that trio of losses that ruins them. Sunday’s was a 20-17 heartbreaker in which Seahawks quarterback Geno Smith scrambled 13 yards for the deciding touchdown with 12 seconds remaining.

Next up is a visit Sunday to the Green Bay Packers, who improved to 7-3 after winning in Chicago 20-19 on a blocked field goal as time expired.

The Seahawks (5-5) snapped a six-game losing streak to the 49ers thanks in massive part to Smith’s heroics on the go-ahead 80-yard drive in the final three minutes. Smith completed 7-of-8 passes on that drive and overcame a sack by Leonard Floyd, all while Nick Bosa remained on the sideline with a hip injury that forced him out in the third quarter.

Remember when defensive issues overshadowed Jauan Jennings’ heroics in last season’s Super Bowl. Well, it happened again this game.

Jennings delivered what should have been a winning touchdown catch earlier in the fourth quarter on a drive that stayed alive with a pair of his third-and-long conversions. Up until Smith’s final touchdown run through the 49ers’ beleaguered defense, no play Sunday was more impressive than when Jennings, on third-and-11, carried four defenders to the 8-yard line for a 13-yard gain to set up his touchdown.

Two snaps later, Brock Purdy faked a handoff and found Jennings open for a 3-yard touchdown and the 49ers’ third go-ahead score of a back-and-forth game. Earlier on the drive, on third-and-11, Jennings made a 14-yard grab at the Seahawks’ 20.

Jennings finished with 10 catches on 11 targets for 91 yards. His final grab was a 5-yarder on third-and-11, and because his second effort wasn’t enough to move the chains, the 49ers punted to renew the Seahawks’ comeback bid.

With 2:38 remaining, the Seahawks took over at their 20-yard line, with 49ers’ pass-rushing star Nick Bosa sidelined since the third quarter by a hip injury. DK Metcalf opened the drive with an 11-yard catch that 49ers coach Kyle Shanahan unsuccessfully challenged. Smith then peppered the 49ers’ defense with an array of completions before finally racing through himself for the winning points.

Earlier, the 49ers defense figured to have locked up this win once they stopped the Seahawks’ on a fourth-and-1 charge at the 49ers’ 37-yard line, with just under four minutes to go. Dee Winters and Ji’Ayir Brown officially got credited for stopping Zach Charbonnet, with other help coming from Maliek Collins and Fred Warner.

The 49ers fell behind 13-10 with 3:25 left in the third quarter, when Kenneth Walker’s 1-yard touchdown run capped the Seahawks’ 70-yard drive, most of which unfolded after Bosa recorded his second sack of the day and exited for treatment on his problematic left hip.

The 49ers’ offense noticeably lacked George Kittle’s pizazz as the All-Pro tight end missed his second game this season with a hamstring injury. They have now lost 11 of the last 14 games he has not played, dating back to November 2020.

After dully taking a 7-6 lead into halftime, the 49ers emerged with an eye-opening play: pass rushers Leonard Floyd and Bosa flushed Smith out of the pocket and he unloaded a sideline pass Isaac Yiadom easily intercepted in Seahawks’ territory.

Yiadom’s return to the 27-yard line put the 49ers in scoring position, and they ultimately cashed in with a 33-yard field goal from Jake Moody for a 10-6 lead. More penalties (holding on Aaron Banks; illegal formation on Jauan Jennings) and another injury (Kyle Juszczyzk) kept that short-field drive from being more potent.

Brock Purdy used his legs to altogether spark, pause and finish the 49ers’ initial scoring drive for a 7-3 lead. He had a 9-yard scramble on then second snap, then after stumbling for a 5-yard loss on a rollout, he promptly raced right and dove to whisk the ball over the goal line around the front right pylon, with 10 seconds left in the first quarter.

It was Purdy’s career-high fourth rushing touchdown, and his fourth in as many games. Through two drives, Purdy’s passing line read 6-of-6 for 43 yards passing, with four completions to Jauan Jennings.

Not to be overlooked, Jake Moody made the point-after kick with new holder Pat O’Donnell, who also stepped in as the punter with Mitch Wishnowsky going on injured reserve Saturday.

At halftime, Christian McCaffrey barely had outgained by Purdy on the ground (37 yards to 32), and that reflected an overall offensive output that was foiled by poor blocks, an interception, a sack, and penalties.

The Seahawks converted their interception Purdy into their second scoring drive, settling for a Jason Myers’ field goal (57 yards) after a third-down sack by Yetur Gross-Matos, who returned from a six-game hiatus. Purdy was intercepted on the 49ers’ third series when a pass to Christian McCaffrey got broken up by Devon Witherspoon and grabbed by defensive tackle Johnathan Hankins at the 49ers’ 29-yard line.

The Seahawks scored first, and it was Nick Bosa producing the third-down sack that led to Jason Myers’ 52-yard field goal; Bosa has a team-leading 6 ½ sacks on the season.

This week in 49ers’ special teams chaos: Jordan Mason muffed a second-quarter kickoff return when the ball ricocheted off his knee and out of bounds, but the 49ers retained possession for an ensuing 7-minute drive that would yield no points but instead multiple penalties, a sack and a punt.