SAN FRANCISCO — Saturday's game started like a dream for Colin Kaepernick — the sort of dream that wakes you up in a sweaty panic in the middle of the night.

Just minutes into the action, on a second-and-6 play from his own 47-yard line, Kaepernick telegraphed a throw off his back foot to tight end Vernon Davis, who was double covered. Green Bay's Sam Shields stepped in front of the pass, caught it with ease and took off toward the end zone. Kaepernick dove for Shields' legs but came up short, and just like that the Packers were up 7-0.

The crowd was stunned. The Packers were amped. And Kaepernick, making his first NFL postseason start, might easily have been wrecked.

He wasn't. The second-year quarterback took a deep breath, coolly trotted back onto the field a moment later, and proceeded to direct a stunning 45-31 victory over the Green Bay Packers at Candlestick Park.

"After that unfortunate interception, I wanted to see what his body language was," center Jonathan Goodwin said. "It was good. He came out confident, took control of the huddle. Led us right down the field for a touchdown."

Indeed, Kaepernick followed the interception by leading the 49ers 80 yards to an answering score, finishing the drive himself with a 20-yard sprint to the end zone.

It was a preview of the rest of the game. Kaepernick would complete 17 of 31 passes for 263 yards and two touchdowns to Michael Crabtree. But he did his best work trampling the Packers with his feet. Kaepernick ran for 181 yards, an NFL record for quarterbacks, postseason or otherwise.

"He was running all over the field," Packers quarterback Aaron Rodgers said. "He's big, strong, athletic, throws the ball well and runs the ball extremely well. We didn't really have an answer for him."

Niners offensive coordinator Greg Roman ran a heavy dose of the Pistol offense — similar to the one Kaepernick ran in college at Nevada. It usually came from a diamond formation, with three teammates around Kaepernick in the backfield, one at each side and one behind him. Frequently, one of those backfield mates was a tight end, who motioned toward the line and provided extra protection.

Kaepernick would then run the read-option, and when he kept the ball, the results were electric. Roman dialed up routes that cleared the middle of the field; much of Kaepernick's yardage came on scrambles up the middle.

With the glib second-year player at the helm, the 49ers rolled up 579 yards of total offense, a franchise postseason record — more than they ever accumulated under John Brodie, or Joe Montana, or Steve Young. Brodie stopped by the Niners' locker room to congratulate Kaepernick afterward.

San Francisco's 323 rushing yards were another team postseason mark.

The scoring went back and forth throughout the first half. The 49ers tied it 7-7 on Kaepernick's 20-yard run; Green Bay went up by a touchdown late in the first quarter on DuJuan Harris' 18-yard run, set up by a 44-yard catch by James Jones; San Francisco tied it again on Crabtree's 12-yard reception, and went ahead 21-14 about 5 ? minutes later on the receiver's 20-yard scoring catch.

The Packers evened it again on Jones' 20-yard reception from Aaron Rodgers; and David Akers, who won a week-long kicking competition with newcomer Billy Cundiff, sent the Niners into the locker room with a 24-21 lead by booting a 36-yard field goal as time expired.

Both of Crabtree's touchdowns were set up by take-aways. Special-teams ace C.J. Spillman pounced on Jeremy Ross' fumbled punt to make the first one easy. Cornerback Tarell Brown intercepted a deep pass by Rodgers and returned it 39 yards to set the stage for the second one.

Mason Crosby tied the game once again, 24-24, in the third quarter with a 31-yard field goal for Green Bay. But the Packers couldn't keep pace after that. Kaepernick got loose for a 56-yard touchdown run — another team playoff record — after a fake to LaMichael James, and set up a scoring plunge by Frank Gore early in the fourth quarter with a 44-yard pass to Davis.

The Packers had to punt after each of those scores, and were never able to narrow the gap.

The 49ers' victory means they move on to the NFC championship game for the second consecutive year, against either the Falcons or the Seahawks. Few people will be worrying about the quarterback's readiness. The Niners have found their man in Kaepernick.

"Everybody that was second guessing the decision to move from Alex (Smith) to him, I don't think they'll be questioning it anymore," safety Donte Whitner said. "... He's our quarterback, he's our leader and he did a great job out there today."

You can reach Staff Writer Phil Barber at 521-5263 or phil.barber@pressdemocrat.com.