NEW YORK — For the second year in a row, the Super Bowl has set a record for American television viewing.

The Nielsen Co. said Monday that an estimated 111 million people watched the Green Bay Packers outlast the Pittsburgh Steelers in professional football’s ultimate game. That tops the 106.5 million who watched the 2010 game between New Orleans and Indianapolis.

The series finale of "M-A-S-H" had held the title of the most-watched TV show in the United States for 27 years. It is now No. 3.

Fox had the advantage of a game between two of the National Football League’s iconic franchises and, even though it looked like it could be a rout when the Packers took a 21-3 lead, it went down to the final minute and held viewers’ interest.

In fact, the most-watched single play of the game was Steelers quarterback Ben Roethlisberger’s final incomplete pass to Mike Wallace with about a minute to go, according to measurements by TiVo Inc., the digital video recorder maker. When that pass hit the ground, it clinched the game for Green Bay.

The five most-watched events in U.S. TV history are now "M-A-S-H" (seen by just under 106 million people on Feb. 28, 1983) and the last four Super Bowls, Nielsen said.

Television ratings in general have been super for the NFL this year, with viewership up 13 percent over last year, Nielsen said. Games on CBS, Fox and NBC averaged 20 million viewers, more than twice what networks get for their prime-time programming.

"Super Bowl XLV caps what is arguably the most successful season that any sports league has ever had," said Pat McDonough, senior vice president for insight and analysis at the Nielsen Co. "The number of people watching NFL games has never been higher, with 24 percent more people watching the average NFL game this year than just five years ago. The Super Bowl continues to be in a category of its own."

Football has become the communal event that television, in a splintered competitive world of dozens of networks, rarely provides outside of "American Idol" or the Oscars. Compelling story lines for the games and the growth in high-definition television help make the games compelling for viewers. The games also tend to be DVR-proof, with viewers wanting to see them live.

Traditions that have built around the game itself make the Super Bowl compelling to non-sports fans. Christina Aguilera’s goof on the National Anthem, the Black-Eyed Peas halftime show and the dozens of commercials that companies debut on TV’s biggest stage were water-cooler discussion topics along with the game on Monday.

Fox’s "Glee" took advantage of the time slot directly after the game, reaching 26.8 million viewers for its special episode. It was the most-watched scripted entertainment program on TV since Fox’s "House" aired after the Super Bowl three years ago, Nielsen said.

TiVo also judged the Snickers commercial featuring Richard Lewis and Roseanne Barr to be the top-rated commercial of the telecast. The company determines that through a calculation that takes in viewership and how many times people rewind their DVRs to watch the ad.

Second place was Best Buy’s ad with Justin Bieber and Ozzy Osbourne.

"Funny ads made it to the top," said Tara Maitra, TiVo’s vice president and general manager for audience research and advertising sales.

The Black-Eyed Peas’ halftime show, with guests Usher and Slash, held its own. TiVo said it had nearly identical viewer engagement numbers as shows with classic rockers over the past two years.

People were much less likely to stop the game to repeat the ads in the second half, when the football action was compelling, Maitra said. No beer ads made TiVo’s top 10 rated ads for the game.

The average Super Bowl viewer with a DVR either paused, rewound or fast-forwarded 145 times during the game, TiVo said.