EUGENE, Ore. -- The Oregon Ducks spent all last week saying they weren't looking past Colorado to next weekend's Pac-12 showdown at USC.

So after the Ducks (No. 4 BCS, No. 2 AP) easily dispatched the Buffaloes 70-14 on Saturday at Autzen Stadium, it was OK to finally talk about the Trojans.

Well, sort of. USC was still just another "faceless opponent" to undefeated Oregon.

"It's a big game, but we treat every game the same," said redshirt freshman quarterback Marcus Mariota, who threw for 136 yards and two touchdowns against Colorado.

The Trojans took some of the drama away from next weekend's game at L.A. Coliseum, losing at Arizona 39-36 later Saturday afternoon.

Oregon players said they would revel in their victory against Colorado for another day before shifting their focus to the Trojans.

Kenjon Barner rushed for 104 yards and two touchdowns, while De'Anthony Thomas rushed for another score and added a 73-yard punt return for a touchdown against the overmatched Buffs. Most of Oregon's offensive starters were pulled by the midway point of the second quarter.

"When you've got Kenjon, De'Anthony, Marcus, you really force people to defend everyone," coach Chip Kelly said.

The Ducks (8-0, 5-0 Pac-12) built a 56-0 lead by halftime and their 70 points are the most they've scored against a conference opponent. It was Oregon's 11th straight overall victory dating to a 38-35 loss at home to USC last season.

Colorado freshman Christian Powell rushed for 127 yards and two touchdowns for the Buffaloes (1-7, 1-4), who lost their fourth straight.