SAN FRANCISCO (AP) -- The balance of power in the NFC West hasn't moved an inch to the south. The Seattle Seahawks are still on top -- just as 308-pound defensive tackle Rocky Bernard illustrated by landing right on poor Alex Smith.
Matt Hasselbeck passed for 281 yards and two touchdowns, Bernard separated Smith's shoulder with a sack on the third play, and the Seahawks remained the best in the West with a 23-3 victory over the struggling 49ers on Sunday.
The 49ers (2-2) were full of cautious optimism during the week. Coach Mike Nolan hoped they were ready to challenge the Seahawks' run of three straight division titles after two wins over Seattle last season, two division victories already this year and an offseason spending spree.
Instead, the Seahawks (3-1) are showing the whole NFL they might be close to their Super Bowl form of 2005. With uniformly solid veteran play and a game plan that anticipated the 49ers' every move, they outgained San Francisco 371-184 and coasted to a blowout win.
"I think we have the most depth and the most experience throughout the conference," said former 49ers linebacker Julian Peterson, who had three of the Seahawks' six sacks. "I think everybody knows that we're the team to beat, but we still have to go out there every week and prove that, so that's what we did."
Deion Branch had seven catches for 130 yards for the Seahawks, while Bernard made the biggest of Seattle's six first-half sacks. The impact separated Smith's right shoulder, likely sidelining him through the 49ers' bye week in mid-October, and the offense was mostly awful with Trent Dilfer in charge.
"They said a few things in the paper this week and they did a few things to us last year that we really took personally," said Bernard, who didn't initially realize he had sidelined Smith. "I saw Trent was in the game and I was like, 'What's up?' It took a while to realize what was going on."
The 49ers know that feeling far too well after struggling offensively through all four games. The offense that failed to gain 200 yards in either of the club's victories didn't have a chance without Smith, who had taken every snap the past two seasons.
Dilfer, who spent four years in Seattle as Hasselbeck's mentor, went 12-of-33 for 128 yards in his first regular-season action since one tough year with Cleveland in 2005.
"It's hard. It's like seeing your little brother go down," Dilfer said. "[The Seahawks] deserve a lot of credit. They put us in a position, whether it be our fault or their good play, where we had to play uphill."
Hasselbeck moved the ball effectively, hitting Bobby Engram and Marcus Pollard with TD passes while Alexander rushed for 78 yards and Josh Brown kicked three field goals. But Seattle's defense won it with two interceptions by Marcus Trufant, solid run-stopping and a game plan to blitz the 49ers silly.
"I'm too old for the revenge thing," coach Mike Holmgren said. "I just was very disappointed in how we played last year. Shoot, this is my home, where I was born and raised and taught school and all those things, coached here. At the very least, I want my teams to come down here and play well."
Frank Gore, who set a franchise record with 212 yards rushing in the Seahawks' last visit to Candlestick, fumbled twice in the first half before finishing with 79 yards.
Thanks to Seattle's sack party, San Francisco had negative total yardage with less than 6 minutes left in the first half. The Niners gained nearly a third of their 87 first-half yards on Michael Robinson's run on the final play of the half.
"In the first two weeks, you get by with it because you win," left tackle Jonas Jennings said. "When you lose, [mistakes] get magnified. We've got to find an identity, because even when we did things well, they didn't work."
The Seahawks' offense also started slowly, managing only one field goal until Branch ran past $80 million cornerback Nate Clements for a 65-yard catch midway through the second quarter. Engram then caught a 17-yard pass over the middle to complete the two-play, 82-yard TD drive.
San Francisco trailed 20-0 before finally scoring on Joe Nedney's field goal late in the third quarter.
Third-string Seahawks RB Alvin Pearman incurred an apparently serious knee injury, though Holmgren won't know its extent until Monday. ... Backup Seahawks QB Seneca Wallace lined up on offense on a handful of plays, throwing a pass, catching an 18-yard throw and running the ball once. "It's a great opportunity to do something to help this team," he said. "I'll do whatever they want me to." ... WR Darrell Jackson, traded to San Francisco in April after seven years in Seattle, had three quiet catches for 38 yards.