No. 3 Oregon 47, Oregon State 19: Marcus Mariota accounted for 406 total yards and six touchdowns as the visiting Ducks kept their College Football Playoff hopes alive by routing the Beavers.

Mariota was 19-of-25 for 367 yards and four touchdowns while adding 39 yards and two scores on the ground for Oregon (11-1, 8-1 Pac-12), which led 30-3 at halftime and will face Arizona in the Pac-12 championship game Friday. Charles Nelson caught two TD passes and Royce Freeman rushed for 135 yards and caught a TD pass as the Ducks cruised to their seventh straight Civil War victory.

Sean Mannion was 19-of-39 for 162 yards in his final game for Oregon State (5-7, 2-7), which lost for the sixth time in its last seven games and failed in its bid to become bowl eligible. Storm Woods rushed 22 times for 128 yards and a touchdown as the Beavers were outgained 365-159 in total yards in the first half.

Mariota bolstered his Heisman Trophy credentials by accounting for four touchdowns in the first half, including a 29-yard pass to Nelson on the Ducks’ first possession. Oregon added a field goal on its next possession and opened the second quarter with TD passes from Mariota to Freeman and Byron Marshall.

Mariota rushed for a 23-yard score with just under 10 minutes left in the second quarter to extend Oregon’s lead to 30-0, and his 1-yard TD run pushed the lead to 40-10 late in the third quarter. Oregon State, which came in ranked second in the Pac-12 in total defense, fell behind 47-17 when Mariota connected with Nelson on a 27-yard TD pass midway through the fourth quarter.

GAME NOTEBOOK: Marshall caught six passes for 131 yards for Oregon, which lost to Arizona 31-24 in Eugene on Oct. 2. The Pac-12 title game will be played in Santa Clara, Calif. … Malcolm Marable averaged 22.9 yards on 10 kick returns for Oregon State, which lost 36-35 at Oregon last season. … The Ducks improved to 14-0 when scoring first under coach Mark Helfrich.