Redshirt freshman Cyler Miles made his first college start and threw for 162 yards and a touchdown for Washington (7-4, 4-4 Pac-12) which clinched a winning record with the victory. Deontae Cooper ran for 166 yards and two TDs and Dwayne Washington ran for 141 yards and two more scores, and the Huskies finished with 530 yards on the ground, second-most for a single game in school history.
It was Washington's biggest margin of victory over the Beavers since a 58-6 win in the 1991 national championship season.
Sean Mannion threw for 229 yards and a score but also threw three interceptions for the Beavers, who lost their fourth straight. The loss snapped a three-game winning streak over the Huskies at Reser Stadium. And it was Oregon State's worst loss since falling 35-0 at Wisconsin in 2011.
Washington was without starting quarterback Keith Price, who injured his right (throwing) shoulder in the second quarter of the Huskies' 41-31 loss to UCLA last weekend. Miles had appeared in six previous games for the Huskies this season, throwing for 250 yards and three touchdowns.
Sankey scored on a 3-yard run to put Washington in front 7-0 early in the game. It was his 32nd career touchdown run, tying him for second on the Huskies' career list with Joe Steele. Sankey edged a touchdown closer to Kaufman with a 5-yard scoring run less than three minutes later that extended Washington's lead.
Travis Coons added a 44-yard field goal to make it 17-0 before the end of the first quarter. Mannion was intercepted under pressure, giving Washington the ball in the red zone and the Huskies went on to score on Coons' 24-yard field goal.
Miles found Kevin Smith in the end zone with a 28-yard pass and Washington went up 27-0 before halftime.
Sankey got his third touchdown on an 8-yard run in the third, before Cooper scored on a 2-yard dash to give the Huskies a 41-0 lead.
The Beavers avoided the shutout early in the fourth quarter when Mannion found Cooks with a 29-yard touchdown pass with 14:40 left in the game. Mannion went into the game leading the nation with an average of 386 yards passing per game and 33 total touchdowns.
Cooks had 117 receiving yards, which gave him 1,560 for the season and put him over Oregon State's single-season record of 1,532 set by Mike Hass in 2005. He already has the school record for receptions with 110 receptions.
Washington pushed their lead to 62-6 with two quick scores, on Cooper's 1-yard run and Dwayne Washington's 32-yard dash. Oregon State answered with Victor Bolden's 98-yard kickoff return and scored again on Chris Brown's 3-yard run to make it 62-20.
Washington added a 71-yard touchdown run for the Huskies before Mannion's backup, Cody Vaz, threw a 33-yard scoring pass to Micah Hatfield for the final margin.
Washington finished with 692 yards in total offense, compared to 414 for Oregon State.
Both teams went into the game having seen their seasons take a downturn.
Washington won its first four games and popped up to No. 15 in the AP Top 25, but the Huskies slumped with consecutive losses to Stanford, Oregon and Arizona State. They've rebounded of late, winning three of their last four.
The Beavers' season got off to a disastrous start, with a loss at home to Eastern Washington in the season opener. Then they reeled off six straight wins, before falling back with losses to Stanford, USC, Arizona State and finally Washington.
Oregon State closes the regular season at Oregon in the annual Civil War rivalry game next Friday. The No. 5 Ducks fell 42-16 on Saturday to Arizona.
Washington wraps up the regular season against Washington State in the Apple Cup. The Cougars became bowl eligible for the first time since 2006 with a 49-37 victory over Utah on Saturday.
The Pac-12 now has nine eligible teams with seven bowl agreements: The Rose Bowl, Alamo, Holiday, Sun, Las Vegas, Fight Hunger and New Mexico. Teams that don't get into one of those bowls would be eligible for an at-large invitation.