LOS ANGELES -- A convincing victory was of little consolation to Southern California quarterback Mark Sanchez, who reacted as if he was on the losing side.
Perhaps he might have been had it not been for the Trojans' dominating defense.
Sanchez passed for one touchdown and ran for another, and No. 8 USC overcame five turnovers and nine penalties to beat Arizona State 28-0 on Saturday for its ninth straight victory over the Sun Devils. The Trojans have won those nine games by an average of 20.1 points.
"It was a tough outing for me and the offense as a whole," Sanchez said. "I think that we beat ourselves. We didn't see anything that we weren't prepared for. We just didn't execute the way we would have liked."
Joe McKnight ran for a career-high 143 yards on 11 carries and Kevin Thomas returned an interception 46 yards for a touchdown for the Trojans (4-1, 2-1 Pac-10), who are 74-9 since the beginning of the 2002 season and have won 41 of their last 42 home games.
Sanchez, whose status was in question for several days because of a bone bruise in his left knee, didn't have one of his better days, completing 13 of 26 passes for 179 yards with three interceptions and a lost fumble -- those turnovers coming on four consecutive possessions in the third quarter. He was relieved by Mitch Mustain with 6:27 to play.
"This game was absolutely about our defense," USC coach Pete Carroll said. "Time and again as the offense made their mistakes, the defense wouldn't have it. This defense is playing incredible minus the penalties. We could have easily been beaten today with some of those mistakes.
"Clearly, Mark was struggling today. He wasn't at his best, but to tell you the truth, we were surprised he played. He continues being a hero out there the way he steps up."
Sanchez looked just fine on USC's first possession, passing for 61 yards before capping an eight-play, 72-yard drive with a 1-yard sneak to give the Trojans a 7-0 lead. He wasn't very productive after that, but didn't need to be. He said the three interceptions were the result of bad throws rather than poor decisions.
Arizona State (2-4, 1-2), meanwhile, has scored just 44 points in losing four straight for the first time since 2003. The Sun Devils gained only 229 yards and committed four turnovers while being shut out for the first time since Oct. 30, 2004, when they lost to California 27-0.
"I don't know if I've ever been around an offensive performance like that in my career," ASU coach Dennis Erickson said. "Give credit to USC. But whenever we get the football like we did in the third quarter as many times as we did, you've got to score points and we didn't. I wish I knew why.
"I can't say enough about our defense. They played well enough to win, but you've got to have all three phases of your game to win."
ASU's Rudy Carpenter, considered doubtful all week because of a sprained left ankle, completed 11-of-20 passes for 126 yards with one interception before limping off the field for good with 8:51 left in the third period.
"I was trying to put it out of my mind and stay positive all week," Carpenter said. "Obviously I wanted to stay and play, but the coach felt it was the right thing to do.
"Defensively we did a good job, but we just couldn't score. Nothing was working."
Backup Danny Sullivan completed just 4-of-17 for 28 yards with two interceptions -- the second by T.J. Bryant on the USC 2-yard line on the game's final play.
Carpenter not only made the start to extend the second-longest active starting streak for a quarterback in the country to 37 games, he completed a 39-yard pass on ASU's first scrimmage play. But the Sun Devils failed to get another first down before having to punt.
Purdue's Curtis Painter made his 38th consecutive start against Ohio State on Saturday.
Neither team posed a serious threat after USC's opening drive until a 38-yard punt return by Kyle Williams gave ASU the ball at midfield early in the second quarter. Helped by a facemask penalty against Clay Matthews, the Sun Devils moved to the 21-yard line before a sack by Thomas and an illegal motion penalty pushed them out of field goal range.
USC scored again just 1:19 later to make it 21-0 on the interception return by Thomas, who stepped in front of wide receiver Michael Jones before sprinting untouched into the end zone for his first career TD.
Stafon Johnson scored on a 2-yard run with 8:09 remaining to cap an eight-play, 92-yard drive and complete the scoring. McKnight had runs of 14, 33 and 20 yards.
Fili Moala blocked field goal attempts of 29 and 48 yards by Thomas Weber following the first two USC turnovers in the third quarter, tying the NCAA record for field goals blocked in a period. Carpenter left shortly before the second blocked field goal -- one play after being sacked for the third time.