MIAMI, Fla. — Who Dat won the Super Bowl? The New Orleans Saints, that’s who.

Ain’t kidding.

Put away those paper bags forever: Drew Brees and the Saints are NFL champions, rallying to upset Peyton Manning and the Indianapolis Colts 31-17 Sunday night in one of pro football’s most thrilling title games.

Brees tied a Super Bowl record with 32 completions, the last a 2-yard slant to Jeremy Shockey for the winning points with 5:42 remaining. The Pro Bowl quarterback was chosen Super Bowl MVP.

“We just believed in ourselves and we knew that we had an entire city and maybe an entire country behind us,” Brees said. “What can I say? I tried to imagine what this moment would be like for a long time and it’s better than expected.”

A surprise onside kick sparked the Saints’ second-half comeback. Their 25th-ranked defense made several key stops, and Tracy Porter’s 74-yard interception return on a pass from Manning, of all people, clinched it.

Manning gave futile chase, but was blocked by a New Orleans defender and fell awkwardly as the cornerback raced by. The four-time NFL MVP forlornly walked to the sideline as the Big Easy celebrations began. Who would have thought the biggest mistake of the game would have come from Manning?

“It’s time for the Saints to celebrate,” he said. “It’s their field and it’s their championship.”

An NFL embarrassment for much of their 43 years, the Saints’ football renaissance, led by Brees and coach Sean Payton, climaxed with Shockey’s touchdown and Lance Moore’s 2-point conversion catch. The conversion pass originally was ruled incomplete, but Payton challenged the call and won.

Porter’s pick, just as dramatic as his interception of Brett Favre’s pass to force overtime in the NFC title game, was the game’s only turnover. It’s one Manning will forever regret.

The Saints (16-3) won three postseason games this winter after winning only two in the previous 42 years. They beat Arizona, Minnesota and Indianapolis (16-3) — all division winners — for their first title, scoring 107 points and allowing only 59.

The championship came 41/2 years after Hurricane Katrina ravaged New Orleans, making the Saints nomads for the 2005 season. There even was some doubt they would return, but the NFL refused to abandon the Big Easy. The Superdome was rebuilt and the Saints won the NFC South in ’06, their first season with Brees and Payton.

That was the season Manning won his only Super Bowl. He had the Colts, favored by 5 points, in front for much of this one, but New Orleans’ league-leading offense, which scored 510 points this season, outscored Indy 31-7 after falling behind 10-0. That matched the biggest comeback in a Super Bowl.

Payton held the Vince Lombardi Trophy high over his head and ran into the end zone toward several hundred fans chanting the Saints’ rally cry: “Who dat, who dat, who dat say gonna beat dem Saints?”

Nobody can say it now.

“Everybody back in New Orleans gets a piece of this trophy,” he said.

“I think I could kiss him,” owner Tom Benson said.

Before many of the 74,059 fans got settled following the Who’s halftime show, the Saints worked a little voodoo. Garrett Hartley’s onside kick was touched by the Colts’ Hank Baskett, then recovered by Chris Reis at the New Orleans 42.

“I just told our guys you’ve got to make me look good on this,” Payton said. “That really becomes like a turnover.”

Looking like the NFL’s most potent offense, the Saints seized the opportunity to take their first lead. It came on Pierre Thomas’ brilliant 16-yard run with a screen pass, capped by a dive into the end zone.

Manning simply shrugged, found Dallas Clark for 45 yards on a 76-yard drive, and Joseph Addai used a spin move a figure skater would envy to score from the 4.

But that was it for Indy.

Hartley, the hero of the NFC title game with his 40-yard field goal in OT, made a 47-yarder later in the third period. After Matt Stover was wide left on a 51-yarder early in the final quarter, Brees led the biggest drive in Saints history.

Manning looked sharp on the Colts’ first two series, taking them 53 yards to a 38-yard field goal by Stover, at 42 the oldest player in Super Bowl history.

Then Manning led a 96-yard, 11-play drive that appeared almost routine, even though it tied the longest march in a Super Bowl. Addai rushed for 53 yards on the series, and Manning found Pierre Garcon behind backup cornerback Osama Young for the 19-yard score on third down.

New Orleans couldn’t match that, but did get a 46-yard field goal by Hartley to make it 10-3. Brees was sacked on third down by All-Pro defensive end Dwight Freeney, who sure looked frisky despite ligament damage in his right ankle that made his availability uncertain for two weeks.

Then Indy’s defense, ranked 18th during the season but staunch in the playoffs, really showed some power. After the Saints marched 71 yards, including 40 yards on two receptions by Marques Colston, New Orleans had third-and-goal at the 1. Mike Bell slipped running right behind All-Pro guard Jahri Evans, and Thomas was stacked up at the line by Gary Brackett and Clint Sessions on fourth down.

But the Colts went against type and ran three times, leaving 35 seconds for the league’s most prolific offense to get in position for Hartley’s 44-yard field goal and a more manageable 10-6 halftime deficit.

Shootout? More like a slowdown. Indy had two three-and-outs and New Orleans had one.

But the points came quickly after halftime — mostly for the Saints.