LOS ANGELES (AP) - Stepfan Taylor ran for the tying touchdown with 38 seconds left in regulation and the go-ahead score in the third overtime, and Stanford's defense preserved its 16-game winning streak by forcing Curtis McNeal's fumble into the end zone to finish a 56-48 victory over No. 20 Southern California on Saturday night.
Andrew Luck burnished his Heisman Trophy credentials by engineering four late scoring drives for No. 4 Stanford (8-0, 6-0 Pac-12), though he nearly cost the Cardinal the game by throwing a crucial interception late in the fourth quarter.
"I was very disappointed in myself," Luck said. "For a couple of seconds, I wanted to go dig a hole and bury myself in it, but guys believed in me. I was so happy to still see time on the game clock. It was another chance to get out there."
Four years after Stanford stunned USC (6-2, 3-2) with a one-point victory as a 41-point underdog, the schools played another classic on a cool Coliseum night _ and once again, the Cardinal ruled.
Both teams scored in the first two overtimes. After Taylor's run in the third OT, Coby Fleener caught the 2-point conversion pass.
USC quickly got to first-and-goal at the 4, but Terrence Stephens forced the ball from McNeal. It squirted into the end zone and A.J. Tarpley jumped on it. After a lengthy Stanford celebration, Luck was among the last players to leave the Coliseum field, sprinting to the locker room while thrusting his arms triumphantly in the air.
Luck passed for 325 yards and three touchdowns and ran for a key score, but the Cardinal were in serious trouble after he made a rare mistake. Nickell Robey intercepted his pass and returned it 33 yards for a score to make it 34-27 with 3:08 left in regulation, but Luck calmly engineered a 76-yard drive capped by Taylor's short score.
Matt Barkley passed for 284 yards and three scores in his third straight loss to Luck. He got the Trojans into Stanford territory in the final seconds of regulation, but Robert Woods used up the final 9 seconds running to the sideline, preventing USC from trying a long field goal. USC coach Lane Kiffin said he was "very disappointed" the officials didn't allow him to call a timeout before it ended.
McNeal rushed for 146 yards and two long second-half touchdowns before committing the key mistake for the bowl-banned Trojans, whose three-game winning streak ended.
The Cardinal were truly tested for the first time since the middle of last season, which ended with an Orange Bowl victory. USC nearly pulled off another upset last season at Stanford Stadium, sticking with the Cardinal until Luck engineered a last-minute drive ending in a field goal for a two-point victory.
Although the bowl-banned Trojans fell agonizingly short of the biggest win in Kiffin's two seasons, USC chipped away much of Stanford's dominant aura accumulated during the nation's longest winning streak.
Stanford fell behind by 10 points in the third quarter, and the Cardinal won by fewer than 25 points for the first time in 11 games since last November. Stanford's defense had limited its last 13 opponents to 21 points or fewer, the school's longest stretch since 1939-41, before USC scored 34 points in regulation.
Stanford had gone three-and-out on offense just four times all season before USC forced three more three-and-outs. Luck had been sacked just twice all season before the Trojans put him down twice, including a huge third-down sack by Devon Kennard that knocked Stanford out of range for a potential tying field goal with less than 9 minutes to play.
The same Trojans defense that yielded 43 points at Arizona State and 41 by Arizona in consecutive games earlier this season played quite well against Luck and the Cardinal until the score ballooned late.
USC took a 20-10 lead shortly after halftime with McNeal's TD runs of 61 and 25 yards. Luck rushed for a go-ahead score in the third quarter, but the Trojans pushed back ahead on Marqise Lee's 28-yard TD catch with 13:04 to play.
Stanford's Eric Whitaker tied it at 27 on a 29-yard field goal with 5:10 left.
Luck rallied the Cardinal back, overcoming his fourth interception of the season to force the first overtime game at the sold-out Coliseum since 2003.
Jeremy Stewart scored on a dive over the line to cap Stanford's first possession of overtime, but Barkley hit Woods in the corner for a 15-yard score to even it. Freshman tight end Randall Telfer turned a short pass from Barkley into a TD to start the second OT, but Luck found Levine Toilolo with a cross-field TD pass moments later, and Whitaker knuckled home the extra point.
Woods had nine catches for 89 yards and a score.
Luck threw early TD passes to Tyler Gaffney and Ryan Hewitt, but he was at his best on the Cardinal's final drive of regulation. He completed 10 straight passes down the stretch, yet still got help after throwing an incompletion on third down near midfield when USC safety T.J. McDonald needlessly leveled receiver Chris Owusu, keeping the drive alive.
After Robey's TD, the Coliseum announcer warned fans in the sold-out stadium against rushing the field after the final gun.
Turns out, that gun was still about an hour away.
Stanford is USC's oldest rival, and the schools have an eventful recent history during the Cardinal's improbable rise as a football power. Stanford posted one of the most shocking upsets in recent college football history here four years ago before a 55-21 rout of USC in 2009 that included the most points allowed in USC history _ until the latest unforgettable night at the Coliseum.