SAN FRANCISCO – The 49ers entered Sunday's game eager to make amends for the wrenching loss to the New York Giants in the NFC Championship Game.

Instead, they made the same mistakes – and some additional ones – that killed their chances nine months ago, and they suffered their worst loss, 26-3, in the Jim Harbaugh era.

"Plan-wise, obviously, it wasn't the right one," Harbaugh said. "And you try to figure out what the next one will be. But, yeah, tough loss, and we have to bounce back fast."

Alex Smith, who completed only one pass to a wide receiver in the championship game, was given two new weapons this offseason, Randy Moss and ex-Giant Mario Manningham, to make sure that never happened again.

Despite the improved firepower, Smith again was overwhelmed by the Giants' coverage. Instead of throwing balls away and at the feet of covered receivers as he did Jan. 22, he threw interceptions – three of them. Smith hadn't been intercepted three times in a game since a December 2009 loss to Philadelphia.

Smith entered the game on a high never achieved before in his career, and his 108.7 passer rating was the best in the league. Against the Giants, he fell back to earth, completing 19 of 30 passes for 200 yards and finishing with a season-worst 43.1 passer rating.

"I didn't feel flat at the beginning of the game. I don't think anyone did," Smith said. "It was more a sense of, when things aren't going well, it's tough. You're out there grinding; you're out there trying to make things happen. When it's not working and you're not playing well, it's not easy to be up."

The Giants (4-2), meanwhile, made all the right adjustments since the championship game.

Safety Antrel Rolle said he and his defensive mates felt they played well Jan. 22 but knew they had to tighten their coverage against Vernon Davis, who had two long touchdown receptions in that game.

Rolle said he warned second-year cornerback Prince Amukamara throughout the week to be wary of the play on which Davis scored the second touchdown. In the second quarter Sunday, the 49ers ran it with another tight end, Delanie Walker, and Amukamara was ready, stepping in front of Walker for an easy interception.

"I kept telling him that that play was going to come," Rolle said. "And he played it to perfection."

Offensive coordinator Greg Roman, who made all the right calls and sent in all the right combinations of personnel in lopsided wins over the New York Jets and Buffalo, had trouble finding a rhythm Sunday. What was genius in previous weeks seemed disjointed against the Giants.

For example, after Smith's only highlight, a 55-yard pass to Moss, appeared to give the 49ers a spark in the third quarter, Colin Kaepernick entered and was sacked for an 11-yard loss.

Harbaugh had few answers.

"The 'Why didn't you throw it deep? Why didn't you run it? Why didn't you do this? Why didn't you do that?' he said. "Don't have all the answers for you right now. The 'should've, would've' is undefeated."

On defense, the 49ers (4-2) again had trouble covering Victor Cruz. He finished with six catches for 58 yards and did his end zone salsa dance after catching a six-yard touchdown pass against cornerback Carlos Rogers in the second quarter.

In the championship game, defensive end Justin Smith and his fellow pass rushers battered quarterback Eli Manning, hitting him 12 times and sacking him six times. Manning wasn't sacked Sunday and was hit only once – early in the game by linebacker Ahmad Brooks.

What's more, Ahmad Bradshaw had two accomplishments rarely seen against the 49ers' defense in recent years. With his one-yard plunge in the third quarter, he became the first running back to score a touchdown against San Francisco's defense this season.

He also finished with 116 rushing yards, the first time a 49ers opponent had broken the 100-yard barrier at Candlestick Park since Tennessee's Chris Johnson did it Nov. 8, 2009.

The 49ers entered Sunday's game ready to avenge last season's loss and show New York they are now the top team in the NFC. Instead, the Giants proved a point.

"We aren't the king of the NFL; the Giants are," Rogers said. "They won the title last year, and they are still the team to beat until somebody else wins the Super Bowl."

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