Heisman Trophy winner Matt Leinart completed 18-of-35 passes for 332 yards with five touchdowns, as Southern California won back-to-back titles and claimed the BCS national championship with a convincing 55-19 win over Oklahoma in the 71st annual Orange Bowl.

Reggie Bush, also a Heisman finalist, rushed for 75 yards on only six carries for the top-ranked Trojans (13-0), who won the AP national title last season and automatically earned the championship from the coaches this year after they were obligated to vote the winner of the Orange Bowl as their national champion.

After this dominating performance, it is also highly certain that Southern California will be the consensus national champion and top the final Associated Press poll for the second year in a row as well. However, there is a slim chance that Auburn could vault into the No. 1 spot in the AP poll, thus creating a split national champion like last year when the Trojans shared the title with LSU, which won the BCS championship.

The Tigers, who are currently third in the AP poll, went 13-0 and capped off their perfect season with a 16-13 win over Virginia Tech in the Sugar Bowl, but probably won't sway enough voters to bypass Southern California for the top spot.

The Trojans were also ranked No. 1 in both the AP and coaches polls last season, but were surprisingly third in the BCS Standings and left out of the championship game in favor of Oklahoma and the Tigers. Southern California, which defeated Michigan in last season's Rose Bowl to earn a piece of the title, left no doubt this year, though, that it belonged in the title game.

Steve Smith hauled in seven receptions for 113 yards with three scores for the Trojans, who claimed their 11th title in school history and also extended the nation's longest winning streak to 22 games.

Dwayne Jarrett added a score and 115 yards receiving on five catches while LenDale White, who battled a sprained right ankle, rushed for 118 yards and two touchdowns in the win.

Jason White, the 2003 Heisman Trophy winner and third-place finisher this season, ended his collegiate career in disappointing fashion. White was 24- of-36 for 244 yards with two touchdowns, but threw three costly interceptions for the Sooners (12-1), who have suffered consecutive setbacks in the BCS title game after also dropping a 21-14 decision to LSU last year.

Freshman running back Adrian Peterson had 82 yards on 25 carries for Oklahoma, which was in search of its eighth national championship in school history and second in the last five seasons. The Sooners defeated Florida State in the 2001 Orange Bowl to earn their last title.

(Agencies)