No. 11 USC used a four-touchdown burst in the second and third quarters to beat Colorado 38-24 Saturday at Folsom Field and secure a spot in the Pac-12 Conference Championship Game.
The Trojans (9-2, 7-1 Pac-12) got two passing touchdowns and a 24-yard rushing score from quarterback Sam Darnold in their mid-game deluge. Coupled with an Ajene Harris interception return for a touchdown just before halftime, USC built a 27-0 lead, shaking off a sluggish offensive start.
Darnold settled in to finish 21-of-34 passing for 329 yards. His scores went 10 yards to Michael Pittman Jr., and 18 yards to Deontay Burnett.
Burnett caught six passes for 79 yards, and Pittman added four catches for 59 yards. Steven Mitchell led the way with four receptions for 91 yards.
Freshman wide receiver Tyler Vaughns caught five passes for 90 yards, including back-to-back acrobatic catches on a scoring drive in the pivotal second quarter.
USC won the Pac-12 South a season after Colorado (5-6, 2-6) was the surprise winner. The Trojans' last conference title came back in 2008.
USC's first drive ended with placekicker Chase McGrath, limited in practice this week by injury, missing a 40-yard field goal. The next saw Colorado stuff running back Aca'Cedric Ware on a fourth-down conversion attempt.
Forcing a punt on USC's third drive, the Buffs appeared poised to spring the potential upset on their senior day. But USC's eruption before halftime gave the Trojans enough breathing room, despite Colorado twice shaving the deficit to two touchdowns in the second half.
The Buffs scored on Steven Montez passes of 78 and 57 yards to wide receiver Juwan Winfree. Running back Phillip Lindsay's goal-line touchdown in the third quarter brought Colorado within 13 -- the closest it had been since USC's 27-0 run -- but a McGrath field goal and a 22-yard touchdown run by Ronald Jones II extended the lead to three touchdowns with 8:46 left in the game.
Winfree's second touchdown reception brought the game to its final score.
NOTES: USC RB Ronald Jones II passed LenDale White, Reggie Bush and Mike Garrett to become the program's sixth-leading rusher at 3,292 yards after Saturday's 142-yard performance. ... Colorado QB Steven Montez passed for at least 345 yards for the third consecutive game with 376. He tallied 347 on Oct. 28 vs. Cal, and 345 on Nov. 4 at Arizona State. ... USC converted 1 of 3 fourth-down conversion attempts. The Trojans came into Saturday's game ranked No. 111 in FBS in fourth-down conversions at 35.3 percent.