The failure occurred shortly after Jacoby Jones returned the opening kickoff of the second half for a 108-yard touchdown, the longest play in Super Bowl history and pushing the Ravens to a commanding lead. But when play resumed, the momentum totally changed.
The Niners scored two straight touchdowns and nearly pulled off a game-winning drive in the closing minutes. They had first down inside the Ravens 10, but Baltimore kept them out of the end zone to preserve the victory.
The blackout, it turned out, became more of a footnote than a spark to what would have been the greatest comeback in Super Bowl history.
"It just took us longer to lose," moaned San Francisco linebacker Ahmad Brooks.
No one could remember anything like this happening in the title game, but it wasn't unprecedented.
Just last season, the Niners endured two power outages during a Monday night game against the Pittsburgh Steelers at Candlestick Park.
"I didn't know what was going on," San Francisco safety Dashon Goldson said. "I just tried to keep my legs warmed up."
The Ravens felt the delay turned what looked like a blowout into a close game. Safety Ed Reed said some of his teammates began to fret as the delay dragged on.
"The bad part is we started talking about it," he said. "Some of the guys were saying, 'They're trying to kill our momentum.' I was like, 'There's two teams on the field.' But once we started talking about it, it happened. We talked it up."
A few of the Ravens threw footballs around to stay loose. Others took a seat on the bench, or sprawled out on the turf.
"I was a little stiff when I got back out there," Baltimore running back Ray Rice conceded. "I'm just glad we were able to finish the game and be world champions."
Finally, the lights came back on throughout the dome and the game resumed.
"Let's go!" referee Jerome Boger barked to the teams.
Monique Richard, who is from the north shore of Lake Pontchartrain, had tickets in the Superdome's upper deck.
"My exact words on the way over here were, 'I hope this goes off without a hitch,' because the city just looked so good, they were doing so well, the weather so good everything was kind of falling into place," she said. "Hopefully, everybody will be understanding."
New Orleans was once a regular in the Super Bowl rotation and hopes to regain that status. The Superdome has undergone $336 million in renovations since Katrina ripped its roof in 2005. Billions have been spent sprucing up downtown, the airport, French Quarter and other areas of the city in the past seven years.
Maybe they forgot one of the basics.
Joked Doug Cook, a Ravens fan from New Orleans: "They didn't pay the light bill."
AP Sports Writer Brett Martel and Associated Press writers Brian Schwaner and Kevin McGill in New Orleans contributed to this story.
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