The 49ers came tantalizingly close to their sixth Super Bowl trip. Instead, that bid literally slipped from their grasp, ending one of their most stunningly successful seasons in franchise history.

In their first-ever overtime playoff game, the 49ers fell 20-17 as the New York Giants capitalized on two fumbled punt returns by Kyle Williams in a rain-soaked NFC Championship Game at Candlestick Park.

"Certainly there's a lot of things to be excited about, to be happy about," 49ers linebacker Patrick Willis said of the 49ers' 14-4, NFC West-winning campaign. "But to fight and get this far, nobody was ready to go home."

Lawrence Tynes' 31-yard field goal with 7:54 into overtime sent the Giants (12-7) into a Super Bowl rematch with the New England Patriots on Feb. 5 in Indianapolis. The Giants upset a previously unbeaten Patriots team 17-14 in the Super Bowl four years ago.

In their finale to coach Jim Harbaugh's remarkable first season, the 49ers blew a 14-10, fourth-quarter lead. And the tide turned decisively on Williams' two fumbles — the first turnovers by the 49ers' special teams all season.

Filling in for an injured Ted Ginn Jr., Williams' latter fumble came at the 49ers' 24-yard line with 9:32 remaining in overtime. He fielded the punt cleanly but got stripped by Jacquian Williams, and Devin Thomas recovered for the Giants.

"I caught the ball, tried to head up field, tried to make a play and it ended up for the worse," Williams said.

Five snaps later, the 49ers' season was done.

"In a lot of ways, we played well enough to win," Harbaugh said. "It'll be a tough one. It'll take a while to get over it, but we will."

Harbaugh then borrowed a quote from Ernest Hemingway and added: "This team is not defeated by any stretch of the imagination. Man can be destroyed but not defeated as long as there's hope."

The Giants' only other victory in five previous playoff games at Candlestick came in the 1990 season's NFC Championship game, when they parlayed a Roger Craig fumble into a deciding field goal for a 15-13 victory.

A chorus of 49ers came to Williams' defense, a fitting sign of unity for a team built on unselfishness.

Quarterback Alex Smith agonized over the offense's 1-for-13 showing on third-down conversions: "It was the difference for us on offense from really controlling that game more. We didn't help our defense enough."

The 49ers' ever-tough defense wished they fared better against Eli Manning, who was 32-of-58 for 316 yards, including a 17-yard touchdown pass to Mario Maningham that put the Giants ahead 17-14 with 8:34 remaining.

"He's a really good quarterback and will make you pay when you lose the turnover differential," defensive lineman Justin Smith said. "It's like that every week. That's how we won a lot of games, and that's how we lost (Sunday)."

That go-ahead touchdown to Manningham was set up by Williams' first lost fumble. A replay challenge that awarded the Giants the ball at the 49ers' 29 after a loose punt bounced off Williams' right knee.

But Williams delivered a 40-yard return on the ensuing kickoff, and the 49ers pulled even at 17 behind David Akers' 25-yard field goal with 5:39 remaining.

"Pretty bummed about losing," 49ers left tackle Joe Staley said. "To be so close really sucks to not come away with it."

Added right tackle Anthony Davis: "Everybody played a part in it. You can't point fingers. That's the easy thing to do. Anybody can point fingers to the next guy, but it's a team game."

Smith admitted that the on-and-off rain affected his 12-for-26, 196-yard outing. After some early showers, Smith said his fingers felt as if he just got out of a bathtub and he licked his fingers to gain more tack.

Two touchdown passes from Smith to Davis set up a 14-10 lead. Eight days earlier, that same Smith-Davis combination produced the 49ers' epic, winning touchdown against the New Orleans in a 36-32 division win at Candlestick.

Giants coach Tom Coughlin, whose team is on a five-game win streak, commended both teams defenses and offered praise for his conquered foes.

"They certainly have a formula that I admire," Coughlin said of the 49ers. "They play great defense, they don't turn the ball over. They were able to have an outstanding season."

This was the 49ers' first in nine seasons that ended in the playoffs, albeit one win short of putting their 5-0 Super Bowl record on the line.

"Yeah, it's difficult," 49ers general manager Trent Baalke said, "but we'll get past it."