Programming note: Watch Monday's 49ers press conference with head coach Jim Harbaugh streaming live online and on Comcast SportsNet Bay Area, today at 2 p.m.
What you need to know: The much-anticipated first match of NFC West rivals turned into a mismatch.
With lightning quickness, the Seattle Seahawks on Sunday night turned a close game at halftime into a 29-3 victory -- another runaway win over the 49ers -- in front of a decibel-popping, record crowd of 68,338 fans at CenturyLink Field.
The Seattle crowd broke the Guinness World Record for loudest stadium with a roar, which reached 136.6 decibels early in the fourth quarter after running back Marshawn Lynch’s second of three touchdowns in the game.
[RELATED: Instant replay -- Seahawks 29, 49ers 3]
The 49ers, coming off an impressive opening-game effort against the Green Bay Packers, were abysmal on offense. Quarterback Colin Kaepernick had the worst game of his 12-start NFL career.
Kaepernick, who threw for 412 yards in the opener, looked out of sync from the beginning. He completed just 13 of 28 passes for 127 yards with no touchdowns and three interceptions. His passer rating was a lowly 20.1. Kaepernick led the 49ers with 87 yards rushing, but he was also sacked three times and lost a fumble.
“I don’t think it was anything they did,” Kaepernick said. “We didn’t come out and perform. We didn’t make plays like we normally do.
“We are not going to win games if I play like that.”
[RELATED: Turnovers, penalties doom 49ers in Seattle]
In the second half, when the game had already spiraled out of control, the 49ers completely lost their composure when Aldon Smith and Anthony Davis were penalized for unnecessary roughness and rookie tight end Vance McDonald was called for unsportsmanlike conduct.
In short, the 49ers were out-coached, out-smarted and overmatched.
“I’m certainly not proud of the way that we played tonight or coached,” 49ers coach Jim Harbaugh said. “It was not our finest hour.”
The 49ers’ best hour after kickoff occurred when the 49ers were in their locker room at a point when play was suspended for a full 60 minutes due to lightning. The 49ers trailed 5-0 at halftime before the Seahawks contributed greatly to an all-around 49ers meltdown.
The 49ers gained just 207 yards of total offense. They were penalized 12 times for 121 yards.
“We lost our composure, and we couldn’t put it together for some reason,” Vernon Davis said.
Was the 49ers’ poor performance an aberration? Hardly. After all, the Seahawks held the 49ers to just 13 points apiece in their 2012 meetings. The 49ers were looking to avenge a 42-13 to the Seahawks last December. Instead, it was more of the same.
The Seahawks’ quest to unseat the 49ers, the back-to-back division champions, got off to an impressive start.
“The scheme worked out really well tonight,” said Seattle coach Pete Carroll, who celebrated his 62nd birthday. “We’ve been practicing this stuff for a long time. They had 62 yards at halftime, and they took every shot they could at us with their scheme. We were really fired up about that.”
In addition to the five turnovers it forced, Seattle’s defense also accounted for the first points of the game when 49ers fullback Bruce Miller was called for holding while he was in the end zone in pass protection for an automatic safety.
“Everything was self-inflicted,” Miller said. “Turnovers, the safety, not-smart penalties. That’s kind of what happened last year. We had a blocked kick for a touchdown. I think these were all self-inflicted wounds. They played good on defense. We just have to stop shooting ourselves in the foot.”
Boldin turnaround: Wide receiver Anquan Boldin was the NFC Offensive Player of the Week after catching 13 passes for 208 yards and a touchdown against the Packers.
But against the Seahawks, the cornerback matched against him for most of the night caught the same number of passes from Kaepernick. Boldin was held to one catch for 7 yards, while cornerback Richard Sherman had one interception, which came on a play in which he was in coverage against tight end Vernon Davis.
Whereas Boldin did his damage against the Packers’ zone defense, he was allowed no room to breathe against Sherman’s physical man coverage.
“That’s just the way we play,” Carroll said. “We put Richard on him a lot in some situations, and that worked out great. He’s a fantastic football player. For our guys to hold him to one (catch), that’s a big night. It took a lot of guys to do that, but Richard had an especially good night on him.”
Said Boldin, “It was nothing that they did. It was us not executing, point blank.”
Kyle Williams was the 49ers' leading receiver with four catches for 39 yards. Rookie Quinton Patton played 13 snaps and was held without a reception.
Play of the Game: The 49ers were in position to get on the scoreboard first after Craig Dahl broke through off the right side to block a Jon Ryan punt in the first quarter.
On a third-and-goal from the Seattle 5-yard line, Kaepernick tried to squeeze in a pass to Davis in the end zone. But cornerback Walter Thurmond, starting for injured Brandon Browner, got his hand on the pass and deflected the ball to safety Earl Thomas for an interception.
“We had gone over it during the week and we thought it was something that we thought we might have,” Kaepernick said. “One of the defenders came off and made a play on the ball and it got deflected into the air.”
Head scratcher: The 49ers were trailing 12-3 in the third quarter after scoring on Phil Dawson’s 21-yard field goal on their previous possession. Seattle faced a third-and-28 and were held well shy of the first down.
But behind the play, 49ers outside linebacker Aldon Smith was called for unnecessary roughness to give Seattle a gift first down. Three plays later, quarterback Russell Wilson found a wide-open Lynch for a 7-yard touchdown and a 19-3 lead.
Injury concerns: Nose tackle Ian Williams is expected to miss at least most of the season with a fractured left ankle, a source said. He sustained the injury on what Harbaugh acknowledged was a legal cut block from right guard J.R. Sweezy.
Safety Eric Reid sustained a concussion upon his big hit on Seattle wide receiver Sidney Rice late in the second quarter. Harbaugh said Reid did not remember the play when the team’s medical staff went to his side. Reid must pass the NFL's protocol on concussions to be cleared to return to action. Reid recorded his second interception of the season in the first quarter.
Defensive lineman Ray McDonald sustained an ankle sprain late in the game. He underwent X-ray, which were negative. It is not known if McDonald will miss any practice or game time.
Vernon Davis sustained a left hamstrings strain while running a deep route that Sherman intercepted early in the fourth quarter.
“I stretch four times a day,” Davis said. “I don’t think it’s anything too crazy.”
No-huddle opening: The 49ers displayed a new wrinkle to open the game, as they debuted a no-huddle offense to help them cope with the crowd noise.
“I think we are very comfortable with it,” Kaepernick said. “I think we moved the ball well when we were in it but once again we had drives that stalled.”
The 49ers abandoned the no-huddle in the middle of the first quarter, and the crowd noise did cause some problems. Boldin had a false start and the 49ers were penalized for delay of game on the team’s third offensive possession. Guard Mike Iupati was called for a false start in the third quarter.
Over-worked defense: The 49ers held Seattle quarterback Russell Wilson in check. He completed just 8 of 19 pass attempts for 142 yards with one touchdown and one interception.
The 49ers wore down in the second half. The Seahawks averaged just 3.7 yards per rushing attempt, but Seattle attempted 47 running plays and rolled up 172 yards. Lynch gained 98 yards and two touchdowns on 28 attempts.
“For the most part, we did get out and stop their pass,” 49ers cornerback Carlos Rogers said. “I think we stood up, for the most part. At the same time, when you come on the road and you’ve got to get more turnovers and put our offense in situations here they can try and score.”
Slow-going for Gore: Running back Frank Gore was held to just 16 yards on nine rushing attempts. In two games, Gore has 60 yards rushing on 30 attempts. Backup Kendall Hunter saw limited playing time through three quarters. He carried just once for minus-7 yards. The offensive line could not generate much room to run against the Seahawks' active front.
"I don't think any of us are proud of our performance tonight," Harbaugh said.
Quote of the day: ”What I saw is that we took this game dead serious and played it like a championship game, just like we did the opener, just like we’re going to go next week and the week after that from now on.”
--Seahawks coach Pete Carroll
Looking Ahead: The 49ers (1-1) return to action Sunday against the Indianapolis Colts (1-1). Of course, Harbaugh recruited and coached Colts second-year quarterback Andrew Luck. Harbaugh did not fare well Sunday against two of his ex-Stanford players. Doug Baldwin had a 51-yard reception and Sherman had a strong game.
“Yes, he (Sherman) came up," Harbaugh said. "I didn't realize it was him until he was kind of moving in the other direction. Yeah, he came up and patted me on the back. I congratulated him and the same with Doug. Let’s congratulate the Seahawks. They played a hell of a game.”