LaMichael James ran for 142 yards before leaving with what appeared to be a left elbow injury, and No. 9 Oregon beat Oregon State 49-21 Saturday to clinch the Pac-12 North and a spot in the conference's first championship game.
The Ducks (10-2, 8-1 Pac-12) will host UCLA on Friday night with a chance to win their third straight conference title and a spot in the Rose Bowl.
The Beavers (3-9, 3-6) aren't going to a bowl game for the second straight season.
James, who went into the 115th Civil War as the nation's top rusher with an average of 142.78 yards per game, was hurt midway through the third when he was hit by Oregon State linebacker Tony Wilson.
The junior running back was already wearing a brace on his right elbow, which he dislocated on Oct. 6 against California. He missed two games because of that injury.
Not long after he left the field on Saturday, James' elbow was wrapped in ice by a trainer. The injury did not appear to be serious because he danced a bit on the sideline with teammate Kenjon Barner during the timeout before the fourth quarter.
Oregon looked as if it was making a strong bid for a spot in the BCS championship game until last weekend, when the Ducks fell to Southern Cal 38-35. But Oregon State didn't give them any trouble.
Darron Thomas threw for 305 yards and four touchdowns.
Versatile freshman De'Anthony Thomas rushed for 71 yards and had 10 caches for 86 yards and a score. Barner ran for 64 yards and a touchdown, and also caught a scoring pass.
Redshirt freshman Sean Mannion threw for 299 yards and three touchdowns for the Beavers. But Oregon State struggled on the ground with just 16 yards rushing, compared to Oregon's 366.
James scored early on a 1-yard run, becoming Oregon's all-time leading scorer with 324 points.
The Beavers tied it at 7 when Jovan Stevenson grabbed a swing pass from Mannion and weaved his way downfield for a touchdown early in the second quarter.
But before the half Oregon scored on Darron Thomas' 16-yard pass to David Paulson and his 8-yard pass to De'Anthony Thomas.
Darron hit Kenjon Barner with another 16-yard TD just before halftime to make it 28-7. Barner ran a yard for another score in the third quarter, and Darron Thomas connected with freshman Colt Lyerla for a 39-yard touchdown early in the fourth.
Mannion threw two TDs in the fourth quarter to Kevin Cummings (19 yards) and Brandin Cooks (23 yards).
Oregon State flanker James Rodgers did not suit up because of a left ankle injury. The Civil War was to be the final game of a college career with some great moments and a severe injury.
In 2007, Rodgers scored on a fly sweep in overtime to give the Beavers a 38-31 victory in the Civil War. Oregon State has not defeated their in-state rival since then.
Rodgers was a fifth-year senior this season coming off a pair of knee surgeries.
Oregon linebacker Dewitt Stuckey (shoulder) and end Dion Jordan (ankle) both played against Oregon State after leaving with injuries against USC.
The Ducks have won four straight Civil Wars. Oregon's winning streak in the series is its longest since 1994-97.
Last weekend's loss to USC at Autzen Stadium snapped a 21-game winning streak at home and a 19-game win streak in conference games. The Ducks haven't lost two straight at home since 2002.