PROVO — No Mike Williams? No Herschel Dennis? No problem for defending co-national champion Southern California.

Meanwhile, problems continue to mount for BYU, which suffered its second lopsided loss to a Pac 10 opponent in as many weeks with a 42-10 defeat at the hands of the top-ranked Trojans late Saturday night at Edwards Stadium.

The woes are familiar foes for the Cougars (1-2) — loss of an early lead, loss of momentum, untimely penalties, turnovers and an oft-ineffective offensive attack.

And all Southern California has needed to do this season is reload, equipping Heisman candidate quarterback Matt Leinart with a host of go-to weapons, despite the loss of heralded wide-out Williams (having signed with a pro agent after expecting to be eligible for the NFL draft) and featured tailback Dennis (having been kept out of games because of a preseason assault charge and making a late-game cameo against the Cougars).

Leinart finished with 22-of-35 passing for 236 yards, two aerial TDs, one interception and his first career rushing score. And Reggie Bush and LenDale White became the first Trojan duo since 1996 to post dual 100-yard efforts — Bush gaining 124 yards on 14 carries and scoring one touchdown on the ground and another on a reception, and White adding 110 yards on 17 carries and his own long-distance TD carry.

With former BYU offensive coordinator Norm Chow calling the Trojan attack, USC (3-0) finished with 527 yards total offense against a BYU defense that came in seventh in the nation against the run and 45th overall in total defense.

BYU managed 221 yards total offense — all but 27 yards in the air. John Beck posted the Cougars' first full-game outing by a BYU quarterback, completing 18-of-34 passes for 221 yards and a 69-yard TD to Todd Watkins but also giving up three interceptions.

Neither team capitalized on interceptions in a scoreless opening period, with BYU's Jon Burbidge picking off Leinart and Trojan linebacker Matt Grootegoed later snagging a Beck pass bobbled by Watkins.

USC came close, but a holding penalty negated a flanker pass from Bush to Steve Smith down to the Cougar 2.

BYU used the same play early in the second quarter on its sole scoring possession of the half, as freshman receiver Austin Collie took a Beck lateral and then threw to Watkins, with USC safety Jason Leach whistled for pass interference in the end zone. The Cougars settled for a Matt Payne 46-yard field goal and a 3-0 lead with 10:30 left before intermission.

But Cougar penalties and turnovers turned into a trio of Trojan touchdowns, starting with back-to-back penalties on the ensuing kickoff that gave USC the ball on 40. And the Trojans needed just two minutes and eight plays to score their first TD, a 21-yard screen pass from Leinart to Bush, who caught the ball just beyond the line of scrimmage and darted through defenders on his way left to the end zone.

BYU dodged a bullet after a Darnell Bing interception of Beck gave the Trojans the ball on the Cougar 30. After getting down to the 17, USC was pushed out of field-goal distance on sacks by Spencer White and Brady Poppinga.

But the Trojans held the Cougars on their next possession and quickly added a second score by Bush, a 66-yard burst from inside out down the right sideline.

Beck and center Lance Reynolds botched the snap and gave the ball back to USC on the Cougar 20. Leinart soon hit a leaping Dwayne Jarrett for a 15-yard scoring strike. Ryan Killeen's third PAT gave USC the 21-3 intermission lead.

After Killen missed his second field goal of the game - this time a 49-yarder — to open the second half, the Cougars answered immediately with a 69-yard bomb from Beck to Watkins, with Payne's PAT drawing BYU to within 21-10. Payne also owned the third quarter's other highlight — a booming 79-yard punt that was one yard shy of the school record.

Capping a 71-yard USC drive, Leinart scored on a 1-yard keeper - his first career rushing TD — in the first minute of the fourth quarter to help push the Trojan lead to 28-10.

After stopping the Cougars on the next possession, USC needed only 48 seconds for a follow-up 71-yard scoring drive, finishing with White turning a would-be tackle behind the line of scrimmage into a slip-through-the-defense 42-yard TD scamper and a 35-10 margin.

USC added its final score in the closing minutes, with fullback Lee Webb blasting up the middle for a 9-yard score, and Killeen added his sixth point-after.