All 73,227 at University of Phoenix Stadium likely expected something unusual from No. 6 Boise State in the Tostitos Fiesta Bowl on Monday night.

But what? And when?

Against No. 4 Texas Christian, the answer came midway through the fourth quarter with the score tied. Boise State punter Kyle Brotzman threw on fourth-and-9 from his 33-yard line. He calmly connected with open tight end Kyle Efaw for 29 yards, leading to the winning touchdown in a 17-10 victory.

The Western Athletic Conference Broncos (14-0) completed their second undefeated season since 2006. They avenged a 17-16 loss last season in San Diego and improved to 2-1 all-time against Mountain West Conference TCU (12-1), all in postseason games.

Boise State joined Ohio State as the only 14-0 teams in college-football history. The Buckeyes capped their 14-0 season with a national-championship win over Miami in the 2003 Fiesta Bowl.

TCU pulled even with 3:42 left in the third quarter on a 29-yard field goal by Ross Evans, and the score remained tied at 10 entering the deciding 15 minutes.

The Horned Frogs drove off their goal line on their first possession of the fourth quarter, advancing from the 2-yard line to the TCU 49 on consecutive passes from quarterback Andy Dalton to Jimmy Young.

Then the game turned when Boise State cornerback Brandyn Thompson, the Defensive Player of the Game, came up with his second interception, leaping in front of wide receiver Antoine Hicks.

The Broncos picked up a first down and then stalled, playing into the hands of coach Chris Petersen, a notorious gambler.

"We shifted into an awkward (punt) formation," Petersen said. "The personal protector makes the call (to punt or pass). As soon as he pointed back to the punter, it was music to our ears. We had what we wanted. We have 10 times more confidence in Kyle (Efaw) than he does in himself. If Brotz is in the vicinity, he's going to make the play."

Efaw, named Offensive Player of the Game, said: "That's a gutsy call. I'm glad it worked. Everyone did their job. They shifted out with it, so we knew it had a good chance. We didn't audible out of it, and Brotz put it on the money."

Quarterback Kellen Moore used the momentum to complete three consecutive passes for a combined 36 yards, then Doug Martin flipped into the end zone for his 15th touchdown of the season.

"We've just had success with them (trick plays) for whatever reason," Petersen said leading up to the game. "We probably don't average more than one a game, if that. Those are the type of plays that people remember."

Such as the Statue of Liberty play for the winning 2-point conversion over Oklahoma, a 43-42 overtime victory, in Boise State's first Fiesta Bowl and Bowl Championship Series appearance.

TCU drove from its 1-yard line with 1:06 remaining to the Boise State 30-yard line before safety Winston Venable intercepted a Dalton pass to put away the Horned Frogs with 18 seconds left.

Boise State confused TCU by using a 3-2-6 defense, and the Horned Frogs had problems in the first half due to faulty headphones that forced the offensive coordinator to move from the press box to the field.

"I had seen them jump from a four-man front to a three-man front," TCU coach Gary Patterson said. "They had done it before, but not the way they did it tonight. They hadn't moved their defensive linemen around. They moved their all-conference corner (Kyle Wilson) to safety in their nickel and dime packages."

Out of sync for the first 28 minutes of the first half, TCU came to life offensively in the final two minutes to score on a five-play, 62-yard drive and trim its deficit to 10-7 at halftime.

Dalton completed passes of 12 and 7 yards as the Horned Frogs drove from their 38-yard line to the Boise State 30. Then off a Dalton pump, wide receiver Curtis Clay got enough separation from Thompson to catch a 30-yard touchdown pass with 49 seconds left.

Thompson was a first-quarter hero for the Broncos, stepping in front of Hicks to intercept a Dalton pass. The junior cornerback had a clear path on his 51-yard return for a touchdown less than four minutes into the game.