Seahawks losing their grip

Kelly Herndon stood at his own 29-yard line, hands on his hips and eyes trained downfield, a portrait of disbelief as he watched the 49ers celebrate.

Unblocked on a third-down blitz, Herndon had 49ers quarterback Alex Smith in his arms only to have the quarterback spin out of a sack and throw a 20-yard touchdown pass to Frank Gore on a play that was as decisive as it was descriptive of Seattle's 24-14 defeat.

The Seahawks simply couldn't wrap up. Not on the play when Smith escaped Herndon to throw the scoring pass that clinched the 49ers' victory, and not in this game when a defense that played so well for the first 45 minutes came undone in the last 15.

Hope didn't float on this sopping-wet night at Qwest Field. It sunk. The Seahawks held the 49ers without a first down for the first 27 minutes only to give up three fourth-quarter TDs.

What happened?

"I don't know," defensive end Grant Wistrom said.

San Francisco running back Frank Gore rushed for 38 yards the first three quarters and 106 in the fourth. The 49ers scored three points in the first three periods and 21 in the final one as a defense known for its fleet feet spent the final period backpedaling.

The Seahawks allowed only five first downs in the first three quarters, held the 49ers to just a field goal and corralled Gore, the player who had run over, around and through them for 212 yards just 25 days ago.

The players were soaked before kickoff, but it was the 49ers who were playing waterlogged, and their only points in the first half came after a fake punt. And then, just as suddenly, the Seahawks came undone.

"We let the big play get on us at the end of the game," linebacker Kevin Bentley said.

It started at the end of the third quarter. The 49ers passed for 116 yards in the first three quarters, 54 on the final play when Smith completed a pass to Arnaz Battle. The 49ers scored on that drive on an 8-yard touchdown pass to tight end Vernon Davis.

This is a defense built around its speed and meant to play with a lead, and suddenly it was back on its heels as the 49ers pushed them down the field their next drive when seven of their first eight plays were rushes.

San Francisco faced third-and-six on Seattle's 20, when Herndon was unblocked on a third-down blitz, Smith in his sights and a sack in his hands. Herndon leaped and made contact, only to have Smith spin out of the sack, take several steps and throw the touchdown pass that pretty much cinched the game.

"I just tried to tackle him, and right at the last second, he dipped back from me," Herndon said. "And then I wasn't hitting him with my shoulder, I started hitting him with my head. So I couldn't wrap him up and he kind of bounced off me a little bit and he made a good play."

Herndon is a player who has made the most of himself, going from an undrafted player who was waived in training camp to being a starting cornerback in the NFL. He is not short on toughness or determination, but on this play he was left staring down the field, his disbelief becoming a still shot of this entire Seahawks season.

The Seahawks had won 10 consecutive division games until they lost in San Francisco on Nov. 19. Now they've lost three in a row.

And after the players left the field into the locker room, Journey's "Don't Stop Believing," was playing over the Qwest Field speakers. But after watching Seattle surrender 21 fourth-quarter points to the 49ers, even the most faithful will be hard-pressed to believe that this morning.

Danny O'Neil: 206-464-2364 or doneil@seattletimes.com