SEATTLE Worst birthday ever.
Jim Harbaugh turned 49 Sunday, then watched his team stumble badly against his arch-nemesis, Pete Carroll, and lose two offensive starters along the way.
With their 42-13 defeat to Seattle the most lopsided of the Harbaugh era the 49ers lost their grip on the No. 2 seed in the playoffs and missed out on their chance to win their second straight NFC West title. They still can take the division by winning Sunday's regular-season finale at home against the Arizona Cardinals, but they would get a first-round bye only with a win coupled with a Green Bay loss to Minnesota.
"It just wasn't good," Harbaugh. "You can't feel like you coached well, you can't feel like you played well after this one."
The 49ers lost tight end Vernon Davis to a concussion after he was leveled by Seahawks safety Kam Chancellor near the goal line. Wide receiver Mario Manningham, back after missing the past two games because of a shoulder injury, was helped off the field in the third quarter and did not return. X-rays on Manningham's knee were negative, Harbaugh said.
Chancellor was called for an illegal hit on Davis, which set up a short David Akers field-goal attempt when the 49ers trailed 14-0. On Sunday, even chip shots went out of control for the 49ers. Defensive lineman Red Bryant blocked the attempt, and it was scooped up by who else? Seattle cornerback Richard Sherman and returned 90 yards for a touchdown.
Sherman became prominent after the teams' first meeting when he was called out by Harbaugh, his coach at Stanford, for his aggressive play. And his presence in the game was in doubt this past week after he had a hearing to appeal a four-game suspension for testing positive for a banned substance.
It was one of several terrible plays for the 49ers, who allowed the Seahawks to score in just two offensive plays and who for the second straight game had trouble holding onto the ball in a steady rain.
Michael Crabtree allowed a pass to slip through his hands as Colin Kaepernick and the offense couldn't establish an early rhythm. Kaepernick missed four of his first five attempts and finished the game 19 of 36 for 244 yards and a touchdown. He was intercepted in the end zone by Sherman early in the fourth quarter when he threw back across his body into the teeth of the Seattle defense.
Frank Gore and Manningham, meanwhile, each lost the ball Manningham's fumble was recovered by the Seahawks while Carlos Rogers dropped an easy interception in the third quarter.
Rogers had a particularly rough game. He was beaten by Doug Baldwin, another Harbaugh protege from Stanford, for a 43-yard reception on the Seahawks' second drive. Rogers later was caught flat-footed on a touchdown toss to running back Marshawn Lynch, and he was in coverage on a touchdown pass to Baldwin in the third quarter, one of two Baldwin touchdowns on the evening.
"It was a punch in the face," Rogers said of the game. "But the thing about it is we still have a chance to win the division, and we're in the playoffs. It's a new season once the playoffs start."
Seattle quarterback Russell Wilson proved to be the most slippery of all. He completed 15 of 21 passes, and the Seahawks converted 11 of 13 third-down attempts. Wilson also hurt the 49ers with his running.
Sunday's game followed a marathon outing by the 49ers in New England. The Patriots ran 92 offensive plays, which essentially is a game and a half. The 49ers had not given up 30-plus points under Harbaugh until last week.
Were the back-to-back trips in prime time too much for the 49ers? None of the players would use that as an excuse.
"I just don't think we made nearly enough plays to even compete in this game," linebacker Patrick Willis said. "And the score shows it."