Ben Gardner forced Southern Cal running back Curtis McNeal to fumble in the third overtime and AJ Tarpley recovered in the end zone as No. 3 Stanford stretched its nation-best winning streak to 16 games with a thrilling 56-48 victory over the host Trojans on Saturday.

Stepfan Taylor scored on a 5-yard run and Andrew Luck hit Coby Fleener for two points in the third overtime before USC reached the 4-yard line and McNeal had the football pried away by Gardner. Tarpley chased it down and dove on it as Stanford improved to 8-0, 6-0 in the Pac-12 North.

USC (6-2, 3-2 Pac-12 South) was in position to notch an upset that would have dented Stanford’s national title aspirations when cornerback Nickell Robey intercepted Luck and returned it 33 yards for a touchdown with 3:08 left in regulation to give the Trojans a 34-27 lead. Luck recovered to lead a 10-play, 76-yard drive with Taylor scoring from 2 yards out to tie it with 38 seconds left.

Stanford, which is No. 6 in the BCS standings, scored on its first overtime possession on Jeremy Stewart’s 1-yard run. USC countered with Matt Barkley’s 15-yard scoring pass to Robert Woods.

Randall Telfer caught a short pass from Barkley and fought to turn it into a 12-yard touchdown to start the second overtime before the Cardinal tied it again on Luck’s 11-yard scoring pass to Levine Toilolo.

The Trojans took a 27-24 lead on Barkley’s 28-yard touchdown pass to Marqise Lee with 13:04 remaining before Stanford's Eric Whitaker kicked a 29-yard field goal with 5:10 left.

USC led 20-10 early in the third quarter on touchdown runs of 61 and 25 yards by McNeal as Stanford trailed for the first time this season. McNeal finished with 145 yards.

Luck finished 28-of-39 for 302 yards; Barkley was 28-of-45 for 286 yards. Both had three touchdowns and an interception.