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Southern California had four chances to go one yard in the waning minutes for a touchdown that would make Notre Dame's unbeaten season awfully uncomfortable.

Just as in so many similar situations in their wildly disappointing season, the Trojans came up short.

Theo Riddick rushed for 146 yards and a touchdown, Kyle Brindza kicked five field goals, and No. 1 Notre Dame earned a spot in the BCS title game with a 22-13 victory over USC on Saturday night.

Notre Dame's impenetrable defense made the decisive stand, keeping USC out of the end zone on four plays from the Irish 1 with 2:33 to play. After three straight runs yielded minuscule gains, freshman Max Wittek threw incomplete to fullback Soma Vainuku, setting off a leaping, chest-bumping celebration on the Notre Dame sideline and in the Irish sections of the sold-out stadium.

The Trojans (7-5) could only lament a season that began with a No. 1 ranking and will end in a lower-tier bowl game after four losses in their last five games.

"I'm disappointed, too," USC coach Lane Kiffin said. "I know those are not our standards here, regardless of the scholarship situation. We have to do better, and that obviously starts with me."

Wittek passed for 186 yards with two interceptions in his first career start for the Trojans, filling in capably for injured Matt Barkley. Marqise Lee caught five passes for 75 yards, yet still broke the Pac-12 single-season receptions record established last year by teammate Robert Woods, who had seven catches for 92 yards.

"For a freshman, Max did a great job," Lee said. "We just had a lot of mistakes again tonight. I made mistakes. We have to get better."

Everett Golson passed for 217 yards as the Irish (12-0) completed their first perfect regular season since 1988, earning a trip to south Florida on Jan. 7 to play for the storied program's first national championship in 24 years. Notre Dame's raucous locker-room celebration reverberated through the thick concrete walls of the 89-year-old Coliseum after an Irish win for the ages.

"I'm still in awe," Irish defensive end Kapron Lewis-Moore said. "I don't think it's hit anybody yet. We're trying to relish the moment."

Although they did little with flash on an electric night at the Coliseum, the Irish woke up more echoes of past Notre Dame greats with a grinding effort in this dynamic intersectional rivalry with USC.

"Well, that's who we are," Notre Dame coach Brian Kelly said. "It's been our defense all year. Our offense is able to manage enough points."

After spending more than a decade looking up at the Trojans, the Irish are back on top of this rivalry with two straight wins in Los Angeles. The school of Knute Rockne, the Four Horsemen and Paul Hornung has new heroes now, from the Heisman Trophy hopeful Te'o to Kelly, who took the Irish from unranked to start the season to No. 1 in the AP Top 25 for the first time in 19 years.

"It's definitely a relief to be able to look at the big picture now, but it's a short window," said Te'o, who had a key interception and became the second Irish defender with three 100-tackle seasons. "We can enjoy this, but then we're going to have to get prepared for one more game."

The grind-it-out win highlighted an unforgettable season for the Irish, who began the year with questions about their relevancy and survived some uninspiring performances and nail-biting finishes with their unbeaten record intact.

Notre Dame is likely to face a Southeastern Conference opponent in Miami, but won't know their identities for another week. Alabama and Georgia play for the SEC title in Atlanta.

With the Irish offense repeatedly stalling in the red zone against the Trojans, Brindza went five for six on field goals, even hitting a 52-yarder at the halftime gun. After Brindza's school record-tying fifth field goal put the Irish up by nine points with 5:58 left, Lee caught a 53-yard pass at the Notre Dame 2.

But after two pass interference penalties, USC failed on three straight runs and an ill-conceived pass against a defense that has allowed just 11 rushing TDs in 30 games.

"They've had a great goal-line defense all year," Kiffin said. "They've done that to everybody down on the goal line. ... It's just so hard to score touchdowns versus them. When the ball is on the 2-inch line, you'd think you could score touchdowns."

Barkley watched from the sideline in a grey hoodie with a sling on his right arm after spraining his shoulder in last week's loss at UCLA. The senior and Pac-12 career passing leader won twice in South Bend during his career, but never got to face the Irish at the Coliseum, sidelined by injuries for both visits.

USC's much-criticized defensive caution under assistant head coach Monte Kiffin was exploited by the Irish, with Golson patiently finding the sags in the Trojans' pass coverage for 181 yards passing in the first half. Riddick went 9 yards for a TD in the first quarter, but USC also stiffened to hold Notre Dame to field goals twice in the red zone.

Notre Dame held its 12th straight opponent without a first-quarter touchdown, but Wittek found Woods for a 9-yard score on the first play of the second quarter — just the ninth touchdown allowed by Notre Dame all season long. The Irish took a 16-10 lead to halftime when Brindza hit the second-longest field goal in Notre Dame history.

Te'o made the seventh interception of his phenomenal season when Wittek threw directly to him on USC's second play of the second half. Both teams struggled to move the ball in the third quarter, and USC settled for a field goal with 9:20 to play just a few moments after Kiffin called a timeout right before a play that ended with Lee appearing to catch a pass on the goal line.