Southern Cal blocked a game-tying 41-yard field goal attempt by Coleman Petersen and returned it for a touchdown on the final play of the game as the Trojans spoiled Utah's Pac-12 debut with a 23-14 victory Saturday in Los Angeles.

The Utes, who joined the Pac-12 from the Mountain West Conference, drove 43 yards on seven plays to set up the field-goal attempt. DaJohn Harris' 68-yard blocked field goal return was originally nullified because of an unsportsmanlike conduct penalty, but the Pac-12 ruled two hours after the game ended that the touchdown should count.

Matt Barkley went 20-of-32 for 263 yards, a touchdown and an interception for the Trojans, who improved to 2-0 after their second narrow victory in as many weeks. USC held off Minnesota 19-17 last week.

This one, much like last week, had its ugly moments. The Trojans turned the ball over three times, including twice in the first half, one of which led to a Utah touchdown that brought the Utes within 10-7 at the half.

The Trojans extended their lead to 17-7 early in the third quarter on Xavier Grimble’s 9-yard touchdown reception, but the Utes responded two possessions later when John White plunged in from the 1 with 6:20 left in the third.

USC’s defense stepped up and forced a fumble and four consecutive Utah punts before the game’s final drive.

Senior running back Marc Tyler, playing his first game after receiving a one-game suspension, finished with 113 yards and a touchdown for the Trojans, who improved to 7-3 all-time against Utah.

The Trojans outgained the Utes 415-320.

Utah quarterback Jordan Wynn finished 23-of-46 for 238 yards and a touchdown.