SEATTLE - The 49ers started hot, played smart and were careful with the ball early on.
But in the Seahawks' home, where their defense waits like wolves for opportunities and where the stadium literally shakes with crowd noise, all it takes is one mistake to turn a well-played game into an avalanche.
That play and the ensuing Seattle feeding frenzy occurred early in the fourth quarter Sunday when the Seahawks converted a fourth-and-7 attempt into a 35-yard touchdown that gave them their first lead of the game. With the crowd suddenly at full throat, the 49ers' final three drives ended with three Colin Kaepernick miscues: fumble, interception, interception.
The 23-17 loss is the third straight punch-to-the gut ending to 49ers' season in the Jim Harbaugh era. This one, however, had two added elements that made it perhaps even more difficult for the 49ers to digest.
It came at the hands of their arch rivals, with the most hated adversary of the bunch, cornerback Richard Sherman, tipping a pass in the end zone that was intercepted with 22 seconds remaining. And it ended with the 49ers' best player, inside linebacker NaVorro Bowman, in the locker room with an ACL injury that is likely to affect his 2014 season as well.
But while there was plenty of disappointment in a quiet 49ers locker room after the game, there also was an element of pride.
"I could sit up here and tell you what you want to hear - that I'm angry, that I'm mad," linebacker Patrick Willis said afterward. "But I'm not going to do that. I'm going to look at you and say, 'You know what? It was a heck of a run.' We fought. We gave everything we had."
Indeed, 'fight' had been the 49ers' key word during the eight-game winning streak they took into Seattle.
In their first two playoff games, the 49ers never flinched when their opponents made big plays and threatened to take over momentum. That trait reappeared in the third quarter Sunday when Seahawks running back Marshawn Lynch rumbled into the end zone on a 40-yard touchdown run, tying the game at 10 and causing CenturyLink Field to tremble.
Kaepernick responded by hitting receiver Michael Crabtree for 22 yards and then scrambling for another 22 yards. Kaepernick's legs were the 49ers' most reliable weapon on Sunday, and he finished with a game-high 130 rushing yards.
On second down and 8 from the Seattle 26-yard line, Kaepernick took off to his right and fired a pass into the end zone for Anquan Boldin, who snatched it over a Seahawks safety Earl Thomas for a touchdown that gave the 49ers the lead right back.
But the 49ers couldn't weather two big, second-half blows by the Seahawks.
The second occurred when Seattle decided not to go for a 53-yard field goal but instead tried to convert a 4th-and-7 scenario from San Francisco's 35-yard line. They not only converted it, quarterback Russell Wilson hit receiver Jermaine Kearse in the end zone against the 49ers defenders, some of whom had given up on the play.
When the 49ers were flagged for holding on the ensuing kickoff and were pinned at their own 11-yard line, the Seahawks had their opponents right where they wanted them.
On third down, Kaepernick scrambled away from pressure. As he wound up to throw, however, defensive end Cliff Avril caught him from behind and dislodged the ball, which the Seahawks recovered and returned to San Francisco's 6-yard line.
The 49ers took over the ball on downs following a goal-line fumble by the Seahawks, but two plays later Kaepernick gave it back again when safety Kam Chancellor undercut his throw to Boldin. The Seahawks converted that turnover into a field goal that put them up by a touchdown.
That set up the 49ers' last-chance attempt to win the game.
Kaepernick had led successful late-game drives in Arizona and Green Bay in recent weeks, and he seemed destined to be the hero again, especially when he converted a fourth-and-2 scenario into a first down with a 22-yard dump off to Frank Gore and then hit Crabtree for 16 yards
"We were in great position," Boldin said. "We were inside the red zone with two time outs left, 40 seconds left. I think we were in good position."
But with Sherman one-on-one against Crabtree, Kaepernick released a pass for the right side of the end zone, the same section where he threw three straight incompletions to Crabtree in the Super Bowl. Crabtree went up for the ball, but Sherman tipped into into the air, allowing linebacker Malcolm Smith to come down with the interception that sealed the 49ers' fate.
"What more could a coach ask for?" Harbaugh said after the game. "They truly believed it. Just one drive, one touchdown and we move on. That's what our guys believed would happen, and we came up short."
-- Matt Barrows