Matt Barkley threw for a school-record six touchdown passes and USC stormed past host Colorado 42-17 on a chilly Friday night in Boulder, Co.

Four of Barkley’s touchdowns came in the first half, as the Trojans (7-2, 4-2 Pac-12) built a 28-10 halftime lead to put the game away early.

USC actually fell behind at the start to the Buffaloes (1-9, 0-6 Pac-12), who used a 37-yard touchdown pass from Tyler Hansen to Toney Clemons on their first possession to claim a 7-0 lead.

But the Trojans rattled off four straight scores, the last of which was a 25-yard pass from Barkley to a wide-open Marqise Lee with just under two minutes remaining in the first half.

Lee and fellow wide receiver Robert Woods each finished with two receiving touchdowns for USC, which topped 30 points for the fifth consecutive game and moved to 6-0 all-time against the Buffaloes.

Barkley — who had already thrown for five scores three times in his career — now has 28 touchdown passes this season. He trails only Houston’s Case Keenum, who leads the nation with 32.

Colorado running back Rodney Stewart broke the school’s career record for all-purpose yardage on a short run in the first quarter. The previous record of 4,351 yards was held by former running back and current offensive coordinator Eric Bieniemy.

The Buffaloes, still in search of their first-ever conference victory as a member of the Pac-12, have lost their last five games by an average of 34.2 points.