NEW ORLEANS -- The Sugar Bowl was a mismatch all right. Just not the one everyone expected.

Utah quarterback Brian Johnson threw for 336 yards and three touchdowns as the No. 7 Utes proved themselves more than worthy of their at-large Bowl Championship Series invite, beating No. 4 Alabama, 31-17, at the Louisiana Superdome on Friday night.

It was the second time in five years the Utes (13-0) crashed the BCS party and came away victorious, matching the feat of the Urban Meyer-coached 2004 squad that crushed Pittsburgh and finished No. 4 in the final Associated Press poll.

That team, though undefeated, didn't garner any national championship talk, just as this year's Utes likely won't, with big-conference schools Florida and Oklahoma set to play in the BCS title game next week.

But Utah, the only undefeated team in the country, made a strong argument for being in the discussion after beating a Crimson Tide group that held the No. 1 ranking in the country for five weeks.

"I know where I'm voting us. I'm voting us No. 1," said Utah coach Kyle Whittingham, whose Utes have the nation's longest winning streak overall (14 games) and in bowls (eight).

Although Alabama (12-2) underwent a revival in Nick Saban's second season with the program, getting back to the Sugar Bowl for the first time in 16 years, its season will largely be remembered for the way it finished with a loss to Florida in the SEC championship game and Friday's upset by the Utes, who were as much as 9-point underdogs.

"I don't think we were ready to play today," Saban said. "I don't know why. They were a very good football team. And I said they were a very good football team 100 times, and I believe that."

The Crimson Tide's biggest question mark entering the game was how it would cope without All-American left tackle Andre Smith, but its problems were primarily defensive.

The Utes spread the field and allowed quarterback Johnson, the Mountain West Conference Offensive Player of the Year, to go to work. Alabama, which entered the game with the third-ranked defense in the Football Bowl Subdivision, didn't have an answer.

Johnson completed 27 of 41 passes. His 336 passing yards were the most the Crimson Tide had allowed all year, passing the 274 Georgia's Matthew Stafford threw for in September.

"I thought this was the best quarterback we played against all year, systematically," Saban said.

Johnson gave Alabama a taste of what it would be facing on three lightning-quick first-quarter drives, none of which lasted longer than two minutes. The senior completed 10 of 14 passes for 139 yards in the quarter, sandwiching touchdown passes to Brent Castell and Bradon Godfrey around a 2-yard direct snap touchdown run by Matt Asiata.

After 11 minutes, Utah led 21-0 in front a stunned Superdome crowd mostly made up for Crimson Tide fans.

Leigh Tiffin's 52-yard field goal to start the second quarter got Alabama on the board before Javier Arenas returned a punt 73 yards for a touchdown to cut Utah's lead to 21-10 heading into halftime.

Linebacker Dont'a Hightower gave Tide additional hope on the first snap of the second half, knocking the ball out of Johnson's hand for a fumble that was recovered by defensive end Bobby Greenwood and returned to the Utah 30.

Three minutes later, Wilson completed a 4-yard touchdown pass to Glen Coffee that got Alabama within 21-17.

But Utah responded with another drive that met little resistance. The Utes went 71 yards in seven plays, needing just a minute and a half before Johnson completed a pass to David Reed, who broke free from cornerback Kareem Jackson and ran free for a 28-yard touchdown that made it 28-17.

Alabama couldn't mount a comeback. Without Smith and his replacement Mike Johnson, who left and didn't return after spraining his right ankle in the first quarter, the Tide had one of its worst offensive showing of the year.

Utah sacked Wilson eight times, double the most Alabama had allowed in any game this year. Wilson threw for 177 yards and a touchdown but was intercepted twice by Utes safety Robert Johnson.

The Tide, which averaged almost 200 rushing yards per game this season, finished with just 31 on Friday night. Coffee, a first-team all-SEC running back, was limited to 13 carries for 36 yards.