MIAMI, Fla. -- By the fourth quarter, the big stadium was half-empty and the college football season ending with a dud. That hardly mattered to Matt Leinart and the Southern California Trojans.
USC versus Oklahoma was touted as a potential classic, but Leinart turned it into a rout instead. The Heisman Trophy winner threw a record five touchdown passes to help the Trojans claim the national championship with a 55-19 victory in the Orange Bowl.
Ranked No. 1 since preseason, the Trojans (13-0) won their second successive Associated Press title and claimed their first BCS championship.
"I think we proved tonight that we are the No. 1 team in the country -- without a doubt," Leinart said.
Oklahoma (12-1), ranked No. 2 all season, lost in the BCS title game for the second year in a row and slipped to third in the final poll behind Auburn, left out of the Orange Bowl despite a 13-0 record. The Tigers could hardly have done worse against USC than the Sooners, who endured the worst drubbing in their proud bowl history.
"We just got whipped," coach Bob Stoops said. "You really soul search as a coach how this could happen."
It happened in part because the Sooners committed five turnovers, and also because they couldn't stop Leinart. He broke the Orange Bowl record of four touchdown passes, throwing three to Steve Smith and one each to Dwayne Jarrett and 260-pound Dominique Byrd.
Leinart finished 18-for-35 for 332 yards.
"When he's on fire, there's nothing the defense can do but sit back and pray," teammate Reggie Bush said.
LenDale White rushed for 118 yards and two scores for the Trojans, who rang up 28 points in barely 10 minutes en route to a 38-10 halftime lead.
USC totaled 525 yards against an Oklahoma defense that allowed no touchdowns in its final three regular-season games. And the Trojans' defense limited Heisman runner-up Adrian Peterson to 82 yards on 25 carries.
"I feel sorry for the crowd," Bush said. "People paid hundreds or thousands of dollars for tickets and didn't see much of a game."
While No. 1 versus No. 2 produced little drama, it did stir speculation about next season -- and the possibility of the Trojans becoming the first team to claim three consecutive AP titles. They've won 22 games in a row and are expected to return many Orange Bowl stars, including Bush, White and Smith -- all sophomores -- and freshman Jarrett. Only four seniors start on defense.
And Leinart? The junior must decide whether to go for the NFL or another Heisman.
"I can't answer right now," he said. "But it's going to take a lot for me to leave."
In the first matchup of Heisman winners, Leinart had the upper hand against Jason White. Leinart threw four touchdown passes in the first half, including three consecutive completions covering 54, 5 and 33 yards.
"He won the Heisman Trophy, so we knew he was good coming in," Oklahoma cornerback Marcus Walker said. "But I didn't know he was that accurate."
The left-hander looked nothing like an overrated quarterback for an average offense, as Sooners defensive end Larry Birdine had described him.
"I did a little chatting during the game with him," Leinart said.
Leinart had plenty of help. Byrd scored on a twisting one-handed grab, and one of Smith's TD catches came as he fell at the back of the end zone.
White, meanwhile, threw two interceptions, but the Sooners' most costly turnover came on a punt return. The kick was about to roll dead near the goal line when Mark Bradley, surrounded by Trojans, scooped up the ball and immediately fumbled.
Fourth-string safety Josh Pinkard recovered at the 6, and White scored on the next play to put USC ahead for good 14-7.
"That was just a bonehead play," Bradley said. "I don't know what I was thinking."
The Trojans didn't need that kind of help. They converted Oklahoma's turnovers into 31 points.
"You have to be responsible with the football," Stoops said, "and we weren't."
USC became the first team to repeat as AP national champions since Nebraska in 1994-95 and joined Florida State in 1999 as the only teams to go wire-to-wire -- from preseason to post bowls -- as No. 1.
"We're definitely on our way to qualifying as a dynasty," Bush said.