LOS ANGELES -- A few minutes after his Stanford teammates left the field, Andrew Luck sprinted toward the Coliseum tunnel with both arms thrust triumphantly skyward, his heart still pounding from 56 points, three overtimes and a season's worth of drama packed into one crazy night.

After nearly a full calendar year of blowout victories, Luck and the Cardinal (No. 6 BCS, No. 4 AP) might have forgotten what a thriller feels like.

Luck loved it all, right down to the final Southern California fumble that ended Stanford's 56-48 triple-overtime victory over the 20th-ranked Trojans on Saturday night.

"I might need a couple minutes to digest it, but it's definitely up there," Luck said when asked where the night ranked among his football memories. "More than anything, I'm just happy to get a win."

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 it.

Luck burnished his Heisman Trophy credentials by engineering four late scoring drives for Stanford (8-0, 6-0 Pac-12), coolly keeping it together after 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, compounding the tension in the sold-out Coliseum. 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.

"No excuse, I just fumbled," said McNeal, who rushed for 145 yards and made second-half touchdown runs of 61 and 25 yards to keep USC in it. "I feel like beating myself up, but I've just got to keep pushing. I'm going to face worse things in life. I just have to keep my head up."

Luck passed for 330 yards and three touchdowns and ran for a key score, but the Cardinal were in serious trouble after he made a rare mistake on his fourth interception of the season, just the second that wasn't off a tipped pass.

Nickell Robey sneaked in front of Chris Owusu and returned it 33 yards for a score to make it 34-27 with 3:08 left in regulation, but Luck swiftly engineered a 76-yard drive capped by Taylor's short score.

"He was so mad at himself," said David Shaw, who's still perfect as Stanford's coach. "He wasn't going to let that play lose the game for us. ... We put the ball in our quarterback's hands, put it on his shoulders, and the kid came through."

Matt Barkley passed for 284 yards and three scores for the bowl-banned Trojans 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 "really disappointed in the officials" when they didn't allow him to call a timeout before it 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.

"It's a great rivalry," Kiffin said. "We've had two great games with them that we haven't been able to finish off."

Although the 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 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.

"We talked about fighting adversity," Shaw said. "I didn't know there was going to be this much adversity, but the kids fought through, and I love them to death for it."

USC took a 20-10 lead shortly after halftime, but Luck rushed for a go-ahead score in the third quarter. The Trojans pushed back ahead on Marqise Lee's 28-yard TD catch with 13:04 to play.

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.

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 Owusu, keeping the drive alive with a personal foul.

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.

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.