SEATTLE -- As the noise grew, coach Pete Carroll looked up through the rain at the deafening home crowd fueling the blowout his Seattle Seahawks were putting together on the field.
After three seasons of breaking down and reconstructing the Seahawks roster, Carroll doesn't have a team that is just going to the postseason. His club reinforced the notion that no one in the NFC wants to see Seattle when the playoffs begin, even as a wild card.
"That crowd was crazy. They were great," Carroll said Sunday night. "And I'm so thrilled we were able to share it with them. They deserve a playoff team and they got it."
Russell Wilson threw a career-high four touchdown passes to move into second place for most TD passes by a rookie. Marshawn Lynch scored two first-quarter TDs, and the Seahawks routed the San Francisco 49ers 42-13.
Richard Sherman returned Red Bryant's blocked field goal 90 yards for another touchdown as the Seahawks (10-5) jumped to a 21-0 lead. That only added to an already hyped crowd on a typically cold and rainy December night, with noise echoing off the walls and overhanging roof of CenturyLink Field that might have been heard all the way across Puget Sound.
No one cared about the cold rain, not with the performance they were seeing on the field. And not with a ticket to the postseason guaranteed thanks to Seattle's first 10-win season since 2007.
"The thing has been happening, it's been coming together," Carroll said. "We're getting better and you can just feel it and see it. It's coming to life for us."
Seattle will likely be the No. 5 seed in the NFC. There remains a slight chance of winning the NFC West, if the Seahawks beat St. Louis in the season finale and Arizona can upset the 49ers in San Francisco.
The Seahawks, 7-0 at home, delayed San Francisco (10-4-1) from celebrating a division title. They turned Jim Harbaugh's 49th birthday into a miserable evening.
Sherman, who played for Harbaugh at Stanford, had a special birthday gift for his former college coach: "I did it with a 90-yard touchdown."
"We beat some pretty good teams and there's no way we thought we were going to beat this team like this. They are a great team. They showed that last week on Sunday night football," Sherman said. "They are an amazing team with a lot of weapons on offense, a great defense so it was a blessing that we were able to get this done, but we expect a different result if we play them again."
Whether home or on the road, the Seahawks are a scary postseason opponent with the way they are playing.
Seattle was the first team since 1950 to score at least 50 points in consecutive weeks thanks to its 58-0 win over Arizona and 50-17 victory against Buffalo. It seemed inconceivable the scoring binge could continue against San Francisco, the best scoring defense in the NFL.
But it did.
Seattle has outscored its last three opponents 150-30.
The 42 points were the most allowed since Harbaugh took over the 49ers, and the most San Francisco yielded since giving up 45 to Atlanta in 2009. It was the perfect way for Carroll to snap a three-game losing streak against his rival.
"It was a lot of points again tonight, and we're just thrilled about it," Carroll said. "Things have just changed. We have changed on offense, and Russell has been a huge part of it, and the coaches allowing it to happen. We don't hold ourselves to points because the standard isn't out there for us. We just try to play really good football and see what happens at the end."
Lynch finished with 111 yards on 26 carries, his third straight game against the 49ers topping 100 yards. Wilson wasn't asked to do much -- other than throw touchdown passes.
Wilson has 25 TD passes, one behind Peyton Manning's NFL rookie record of 26. He finished 15 of 21 for 171 yards. His only incompletion in the first half was a deflected pass that Patrick Willis intercepted.
Wilson led Seattle on scoring drives of 9, 12, 13 and 15 plays. He was never threatened by Aldon Smith, who remained stuck on 19½ sacks for the season because of the play of Seattle left tackle Russell Okung.
The Seahawks were 11 of 13 on third-down conversions. Wilson was the clear winner in the matchup of young quarterbacks.
"If you capitalize on third down and capitalize in the red zone it's tough to beat us. That attention to detail that we've had all week prepared us to play a great game and it showed against a very, very good football team," Wilson said. "For us to do what we did at home in front of all our amazing fans is pretty special."
San Francisco's Colin Kaepernick had already proven himself capable of winning on the road with victories in New Orleans and last week in New England. But Seattle is a different beast, widely regarded by players as the loudest venue in the NFL. His inexperience playing in such an environment showed. He was flustered and disorganized at the line of scrimmage, letting the noise from Seattle's fans affect him.
Kaepernick finished 19 of 36 for 244 yards and a late TD pass, but his forgettable night was capped when Sherman stepped in front of his pass for Randy Moss at the back of the end zone on the first play of the fourth quarter for his seventh interception of the season.
"I think we could have done better," Harbaugh said. "I don't think there was any part that we can really feel good about right now."
San Francisco RB Frank Gore had just 28 yards on six carries after rushing for a season-high 131 when the teams met in Week 7. ... 49ers TE Vernon Davis (concussion) and WR Mario Manningham (knee) both left with injuries and didn't return. ... Seattle last went undefeated at home in 2005. ... Baldwin's last TD catch came in Week 6 vs. New England.