* Ravens' Flacco named Super Bowl's most valuable player
* Power outage saps Ravens' momentum, sparks 49ers rally (Updates with details, quotes)
By Steve Ginsburg
NEW ORLEANS, Feb 3 (Reuters) - The Baltimore Ravens survived a furious second-half rally by San Francisco and a momentum-sapping power outage at the Superdome to defeat the gritty 49ers 34-31 in the Super Bowl on Sunday.
A Super Bowl-record 108-yard kickoff return for a touchdown by Jacoby Jones to open the second half gave the Ravens a 28-6 but the 49ers quickly scored 17 straight points after a 35-minute power outage and nearly pulled off a stunning comeback.
"Both teams had to deal with it," Ravens coach John Harbaugh said of the power outage. "They dealt with it better, obviously. They were able to turn the momentum of the game."
Trailing 34-29, the 49ers marched down to the Ravens' seven but failed to score on four tries, surrendering the ball on downs at the five with 1:42 remaining.
Baltimore used up the clock and on fourth down, punter Sam Koch ran out of the end zone for a safety with four seconds left.
Joe Flacco, the game's Most Valuable Player, completed 22 of 33 passes for 287 yards, three touchdowns and no interceptions to lead the Ravens to their first title since the 2000 season.
"We don't make anything easy," said Flacco, who has guided the Ravens to the playoffs in each of his five NFL seasons. "It was a hard-fought game on both sides.
"We gave the country a pretty good game to watch. Not to our liking necessarily but that's the way it goes sometimes and that's the way we do things."
Baltimore's lead evaporated because the 49ers' talented second-year quarterback, Colin Kaepernick, suddenly found the form that made him one of the league's most dangerous big-play threats.
Despite a shaky first half, Kaepernick completed 16 of 28 passes for 302 yards and a touchdown. He also ran for 62 yards and a 15-yard touchdown on seven carries to finish behind Frank Gore (110 yards) as the 49ers' second-leading ground gainer.
Kaepernick's rushing score with 2:57 left cut the Baltimore lead to 31-29 but his pass attempt on the two-point conversion attempt was incomplete.
A 38-yard field goal by Justin Tucker with 4:19 left in the game hiked the Ravens' lead to 34-29, setting the stage for what could have been a Super Bowl-record comeback by the 49ers.
But the Ravens' defense, anchored by retiring future Hall of Fame linebacker Ray Lewis, came up big when it had to with a goal-line stand that handed the 49ers' franchise its first Super Bowl loss after five victories.
"I made too many mistakes for us to win," Kaepernick said softly.
"Our guys battled, they competed," said 49ers coach Jim Harbaugh, who also lost the Super Bowl of sibling rivalry because his brother John coaches the Ravens.
"We got a spark and we weren't going to look back after that. We battled right to the brink of winning."
Baltimore linebacker Terrell Suggs said it was the "ultimate cake" to allow Lewis, a 13-time Pro Bowler and the team's inspirational leader, to go out a winner.
"There will never be another leader like him and we sent him out like his brothers," he said. "His legacy will go untainted."
Ravens tight end Dennis Pitta, who caught four passes for 26 yards and a touchdown, said the power outage, which left half of the overheard lights in the Superdome out, "felt like an hour."
"We lost a lot of momentum and, credit to them, they came storming back and played tremendous. But this team continued to fight and never quit ... Didn't make it easy, but it was fun."
Baltimore was outscored 25-6 after the lights went out and the raucous pro-Ravens crowd, which had brought a Mardi Gras-style celebration from nearby Bourbon Street into the Superdome, got eerily quiet.
Ravens wide receiver Torrey Smith blamed Beyonce's rockin' halftime show for his team's meltdown.
"Beyonce must have been good - she took all of the power with her when she left the stage," he said. "It was tough. But we had to deal with the same thing that San Francisco had to. And they responded well."
Lewis said his children will be his top priority in retirement.
"Daddy gets to come home now," he said. "I get to chase them. They aren't going to like me being home all the time. This is the most ultimate feeling ever.
"This is the way you do it. No other way to go out and end a career."
The Ravens' John Harbaugh said it was troubling to shake hands with his brother on the field after the game.
"The meeting with Jim in the middle was probably the most difficult thing I have ever been associated with in my life," he said. "I am proud of him." (Editing by Frank Pingue)