TEMPE, Ariz. -- USC is back in the defense business.
Will Harris returned an interception 55 yards for a touchdown -- one of four turnovers forced by the Trojans -- and No. 12 USC held on for a shaky 14-9 victory over Arizona State on Saturday night.
A week ago, the Trojans' once-proud defense conceded 47 points to Oregon in the worst loss in the Carroll era. The defense regrouped against an ASU team with relatively little firepower.
"That last game against Oregon, it made us realize that we've got to come back and do things right, and that's what we did," said Harris, who also picked off a desperation pass in the end zone as time expired.
USC hadn't lost back-to-back games since a four-game skid in Carroll's first year, 2001.
Thanks to the defense, it still hasn't.
With nine penalties for 98 yards, USC did all it could to keep ASU in the game. But the Trojans (7-2, 4-2 Pac-10) survived and stayed in the hunt for an eighth straight Bowl Championship Series berth.
"We were determined to win the football game from start to finish, and do stuff that it took to win," Carroll said. "On this night, it took a great defensive effort."
Matt Barkley threw a 75-yard pass to Damian Williams for what turned out to be the decisive score, but Barkley also put his team in a tight spot with his lone interception, in the fourth quarter. He completed 7 of 22 passes for 112 yards and a touchdown.
With USC's offense sputtering behind Barkley, the Trojans turned to a unit that seemed helpless in a 47-20 loss at Eugene one week earlier.
"To get back on track defensively is really obviously important to us," Carroll said. "It's such a good night to get four turnovers."
The defense responded as USC defeated ASU (4-5, 2-4) for the 10th straight time. But early on it looked like a rerun of the Oregon debacle.
On the opening possession, the Trojans let the punchless Sun Devils march to the USC 13-yard line before freshman tailback Cameron Marshall fumbled on a hit by Christian Tupou. USC cornerback Josh Pinkard recovered.
ASU threatened again late in the second quarter but had to settle for a 21-yard field goal by Thomas Weber.
Then USC's defense turned in the pivotal play.
Harris picked off a Danny Sullivan pass along the left sideline and romped 55 yards for a touchdown. Harris said he could tell by ASU's formation that a quick pass was coming.
"I hopped it," he said.
ASU coach Dennis Erickson was still fuming about the play after the game.
"To throw the pick six is ... ridiculous," Erickson said.
Harris was also flagged 15 yards for unsportsmanlike conduct for high-stepping into the end zone.
USC made it 14-3 on an electrifying play early in the second half.
On second and nine at the USC 25, Barkley dumped the ball to Williams in the right flat. Williams waited for his blockers, then cut back across the field and streaked toward the goalline.
ASU cornerback Terell Carr pushed Williams out of bounds as he stretched the football toward the pylon. The officials ruled Williams out at the 2, but USC was awarded a touchdown on review.
That put the Trojans ahead 14-3.
At that point, Erickson pulled Sullivan and brought in 6-foot-8 freshman Brock Osweiler, bringing cheers from the crowd. Sullivan was 12 of 23 for 113 yards, and he threw two interceptions.
This was the change many ASU fans had demanded for weeks. It took three possessions for the Sun Devils to respond.
Osweiler led ASU 80 yards in eight plays, completing all three of his passes for 65 yards. Osweiler kept the drive alive by stiff-arming a tackler and picking up six yards on a bootleg on third-and-3.
Then he found a wide-open Chris McGaha for a 23-yard touchdown in the final minute of the third quarter. USC led 14-9 after Pinkard blocked the point-after try.
Osweiler went 11 for 27 for 153 yards and a score, and he was intercepted once.
"There was opportunities for myself to make plays," Osweiler said. "I didn't get the job done."
ASU fell to 3-28 against the Top 25 since 2000 -- and 1-7 under Erickson.
With USC clinging to a five-point lead midway through the fourth quarter, USC came up with another big stop.
The Sun Devils took over at USC's 36 after a fluke interception by ASU's Clint Floyd. Barkley threw into traffic, and ASU's Mike Nixon deflected the pass.
The ball caromed to USC's Brice Butler, who juggled the ball as he collided with a teammate. The ball popped loose, and ASU's Terell Carr kicked it a foot or so off the turf before Floyd finally latched onto it.
USC dodged that bullet, thanks to an offensive holding call and three misses by Osweiler. who was under heavy pressure.
ASU had one last shot at the upset, taking over at its 22 with 1:56 to play and no timeouts. The Sun Devils reached the USC 45 with 7 seconds left, but Harris picked off Osweiler's pass into the end zone as time expired.
"I hope we can capitalize on this and keep moving forward," Carroll said.