Rarely rattled on an impressive path to the Super Bowl, San Francisco’s second-year quarterback finally showed some inexperience on football’s big stage. Not to mention some guts.

After a remarkable postseason run — with those speedy legs — by the tattooed play-caller, the Baltimore Ravens exposed plenty of flaws in handing Kaepernick and Co. a 34-31 loss Sunday despite San Francisco’s second-half rally.

“We were ready for the second half,” Kaepernick said. “We knew we had to score to get back in the game. We had good plays, we had bad plays in the red zone.”

No team has come from more than 10 points down to win a Super Bowl, and Kaepernick had a chance to make it happen less than three months after becoming San Francisco’s starter.

He regrouped during a 34-minute delay early in the third quarter because of a power outage, finding his groove and turning the Super Bowl into a wild game down the stretch — and gave yet more cred to the pistol offense designed by his old college coach that is so well suited for the NFL’s young, mobile quarterbacks.

“Colin was cool the entire game,” left tackle Joe Staley said. “Colin was the same he’s been the whole entire season. He’s never shown any hints of being rattled, any hint of being uncomfortable on the football field, and he showed that exact kind of character today.”

Kaepernick directed four second-half scoring drives, throwing a 31-yard touchdown pass to Michael Crabtree and also running 15 yards for a TD. But the 49ers missed the two-point conversion that would have tied the game with less than 10 minutes left.

Crabtree didn’t get much help in a mistake-filled first half by San Francisco (13-5-1), which failed to stop Joe Flacco and deliver the franchise’s sixth championship that would have matched the Pittsburgh Steelers for most ever.

The 49ers’ perfect Super Bowl record? That’s over, too. They lost for the first time in the title game.

Perhaps it’s a bit premature to begin talking Bay Area dynasty again — in football, at least.

Playing for a title for the first time since Hall of Famers Steve Young and Jerry Rice won with a rout of San Diego 18 years ago, Jim Harbaugh’s Niners made costly mistakes on both sides of the ball early in the game. And special teams, too.

Yet Kaepernick did a little bit of everything in San Francisco’s final drive, when the 49ers got the ball back at their own 20 with 4:19 remaining and trailing 34-29. He ran for 8 yards, hit Crabtree on a 24-yard gain and handed off to Frank Gore for a 33-yard run to the Baltimore 7.

But with three chances from the 5, Kaepernick threw three straight incomplete passes intended for Crabtree, who got tangled up with a defender on the final play but no holding was called — Harbaugh screamed from the sideline and signaled for a penalty.

Kaepernick’s off-balance throw under pressure on fourth down sailed through the end zone. Kaepernick lowered his head slightly and walked slowly off the field.

“That wasn’t the original option,” Kaepernick said. “It’s something I audibled to at the line based on the look they gave us.”

No comeback this time in the Big Easy.

The 49ers had a pair of penalties in the opening 4:24 that proved costly, on each side of the ball — Vernon Davis’ flag for illegal formation on the first play from scrimmage to negate his own 20-yard catch, then linebacker Ahmad Brooks’ offside on Baltimore’s third-and-9 from the 18. That gave the Ravens 5 yards, Flacco found Anquan Boldin for 13-yard touchdown the very next play.

Early in the second quarter, rookie LaMichael James made a 25-yard run in which he spun twice before losing the ball. And safety Donte Whitner received a 15-yard facemask penalty to give the Ravens first-and-goal on the 4. Flacco found Dennis Pitta for a 1-yard score two plays later.

Kaepernick wound up 16 for 28 for 302 yards with three sacks and an interception for a 91.7 passer rating in his outstanding Super Bowl debut. The interception was the first by the 49ers in six Super Bowls and ended a streak at 169 passes without one.

Kaepernick also rushed for 62 yards, joining Joe Montana as the only quarterbacks to pass for 300 yards and run for 50 in a Super Bowl. Kaepernick recorded the fourth 300-yard passing performance by the 49ers in the Super Bowl — Montana had two and Young one.

The 25-year-old completed 8 of 13 first-half passes, was sacked twice and threw an interception as San Francisco fell behind 21-6.

In the NFC championship game at Atlanta two weeks ago, such a deficit was no problem. Kaepernick rallied the Niners back from 17-0, while the defense delivered by holding the Falcons scoreless in the second half to win 28-24.

On Sunday, Kaepernick led his team into the end zone for the first time with 7:20 remaining in the third quarter after the power outage when he found Crabtree.

But a stingy San Francisco defense that relied on its ball-hawking, run-stopping play all season, couldn’t consistently slow down Flacco and the high-powered Ravens.

Leading up to the Super Bowl, Kaepernick had handled himself beautifully in hostile environments — beating Drew Brees and the Saints right here in the Superdome on Nov. 25, and later guiding the Niners at New England. And, of course, the win against the Falcons on Jan. 20 that returned San Francisco to the Super Bowl at last.

“I was just sitting there watching Kaep with the ball and knowing that this whole team has trust in him and that he had everything in his hands,” Jean Francois said. “We just knew that the ball was going in the end zone, through Frank, through Kaep, even getting the ball to Randy (Moss) or Crabtree with the hands he has.”

The 49ers were hoping for their own downtown victory parade and to have the World Series champion Giants take part after Harbaugh and quarterback Alex Smith drove in the San Francisco baseball team’s parade last fall.

San Francisco would have become the first market to win a World Series and Super Bowl in the same season since the Boston Red Sox accomplished it in 2004 and the New England Patriots followed suit in February 2005.