Marcio Jose Sanchez, Associated Press
Southern California quarterback Matt Barkley throws against Stanford during the first half of an NCAA college football game in Stanford, Calif., Saturday, Sept. 15, 2012.
STANFORD, Calif. — Even without Andrew Luck, Stanford still has every answer for Matt Barkley and Southern California.
Josh Nunes threw a go-ahead 37-yard touchdown to Zach Ertz, Stepfan Taylor ran for 153 yards and scored two touchdowns, and No. 21 Stanford upset second-ranked USC 21-14 on Saturday night for its fourth straight win in this series.
Heisman Trophy hopeful Matt Barkley threw for 254 yards and two interceptions while completing only 20 of 41 passes. He was sacked twice on the final drive for the Trojans (2-1, 0-1 Pac-12) and threw out of bounds on a final, desperate heave on fourth-and-39 from USC's 25-yard line.
The Cardinal (3-0, 1-0) are 3-0 for the third straight season for the first time since 1970-72, and have their longest winning streak ever against the Trojans.