Matt Barkley’s six touchdown passes lead USC over Colorado

Reporting from Boulder, Colo. -- If USC was feeling any letdown after its heart-wrenching loss to Stanford, the Trojans came to the right place to rejuvenate.

Nothing like some clean mountain air, a struggling opponent and a national television audience watching in 3-D to help erase the emotional hangover.

No one felt more refreshed than quarterback Matt Barkley.

The junior passed for a school-record six touchdowns as the No. 21 Trojans cruised to a 42-17 victory Friday night before 50,083 at Folsom Field.

On a night when Trojans Coach Lane Kiffin went all in with his youth movement, Barkley surpassed Rodney Peete, Carson Palmer, Matt Leinart and Mark Sanchez by passing for more than five touchdowns.

“To finally get six is a pretty cool feeling, knowing you’re up there with some of the greatest quarterbacks in college football history,” Barkley said. “I don’t think I’m close to what those guys have done in their careers.

“It’s just more motivation for me to do better.”

Robert Woods and Marqise Lee each caught two touchdown passes and tight end Xavier Grimble and tailback Amir Carlisle each had one as USC improved to 7-2 overall and 4-2 in the Pacific 12 Conference.

Barkley had passed for four touchdowns by halftime as the Trojans built a 28-10 lead. He finished 25 of 39 passes for 318 yards, with one interception.

Kiffin was happy for Barkley, but accurately described his performance as “up and down, as crazy as that sounds.”

It had been a short but eventful week for the Trojans, who were coming off a 56-48 triple-overtime loss to Stanford.

The Pac-12 fined Coach Kiffin $10,000 for criticizing officials and handed safety T.J. McDonald a half-game suspension for an illegal hit on a Stanford receiver.

“It had been referred to as a trap game,” Kiffin said. “It’s good to see our guys simply play well.”

Kiffin, perhaps looking ahead to next season and oncoming scholarship limitations, started five first-year freshmen and two redshirt freshmen.

Lamar Dawson supplanted senior Chris Galippo at middle linebacker and Tre Madden started in place of injured Dion Bailey. Hayes Pullard qualified as the veteran of the group as a redshirt freshman.

“I played solid,” said Dawson, who had four tackles. “We just moved on from that loss and came out ready to play.”

It didn’t look that way at the outset.

Colorado (1-9, 0-6 in conference play) knocked the Trojans off the line of scrimmage on the opening possession, reminding of the Trojans’ 2008 Thursday night upset loss at Oregon State.

But the Buffaloes had no answer for USC’s speedier receivers.

Woods and Lee each caught nine passes, Woods for 130 yards, Lee for 124.

“USC had a good strategy with their [bootlegs], play-action fakes, and they were able to find open receivers and convert some crucial third downs,” Colorado linebacker Derrick Webb said. “That was the difference in the game.”

Colorado quarterback Tyler Hansen and running back Rodney Stewart had their moments, but the Trojans stalled drives and blocked two field goal attempts.

Hansen, a senior from Murietta, completed 17 of 37 passes for 250 yards and two touchdowns, both to receiver Toney Clemons.

Clemons’ second touchdown early in the fourth quarter pulled the Buffaloes to within 35-17, but Carlisle gave Barkley his record by taking a screen pass over the middle and turning it into a 19-yard scoring play for a 42-17 lead.

“It was awesome,” Barkley said. “The screen finally worked.”

USC, which had 243 yards rushing, built a 28-10 halftime lead behind Barkley, who has passed for 28 touchdowns this season.

Colorado scored on the first possession on Hansen’s 37-yard strike over the middle to Clemons, giving the Buffaloes a lead for the first time since Oct 1 against Washington State.

Barkley misfired long on his first pass, but then completed his next four, including a perfectly lofted 33-yard touchdown to Lee.

USC went ahead to stay on Barkley’s short touchdown pass to Grimble early in the second quarter and then increased the margin to 14 points on Barkley’s 15-yard strike to Woods.

Lee dropped a certain 50-yard touchdown pass later in the quarter, but Barkley found him for a 25-yard touchdown and a 28-7 lead. Colorado added a field goal with one second left after Barkley’s interception.

USC now must negotiate a final quarter of the season with games against Washington, sixth-ranked Oregon and UCLA.

gary.klein@latimes.com

Twitter.com/latimesklein