SEATTLE (AP) Sean Mannion returned with a chance to lead Oregon State to a mark never before reached in school history.
Instead, the biggest surprise in the Pac-12 Conference this season finally stumbled, and that was because of shaky play from its quarterback.
Photos: Beavers upset by Huskies 20-17
Bishop Sankey ran for 92 yards and two touchdowns, Travis Coons kicked a 30-yard field goal with 1:20 left and Washington took advantage of four interceptions from Mannion in a 20-17 upset of the seventh-ranked Beavers on Saturday night.
"It was a combination of things that went wrong," Mannion said. "I misread some things. I'll learn from it and make better plays next time."
Oregon State (6-1, 4-1 Pac-12) was trying for the first 7-0 start in school history. Instead it became the second AP Top 10 team to be upset by the Huskies at home this season. Washington knocked off then-No. 8 Stanford 17-13 in late September.
Washington's pride was wounded after three straight losses to Oregon, USC and Arizona by a combined score of 128-52. The Huskies found their resiliency in time to end the Beavers unexpected dream start.
"We needed it just for our own wellbeing," Washington coach Steve Sarkisian said. "It wasn't just about the record at the end it was for what's inside of us. Pride is a powerful thing and you earn pride, it's not given and we earned it tonight."
Mannion, returning from minor knee surgery, threw interceptions on consecutive possessions early in the fourth quarter after Oregon State had rallied from a 10-0 halftime deficit to pull even with a dominating third quarter. The last of Mannion's four picks was snagged by Marcus Peters and two plays later Sankey scored from the 1 to give Washington (4-4, 2-3) a 17-10 lead with 8:19 remaining.
Oregon State backup quarterback Cody Vaz entered and threw a 29-yard TD pass to Connor Hamlett with 4:58 left to pull the Beavers even. But Keith Price led the Huskies 63 yards in 3:38 for Coons' go-ahead field goal and snapped Washington's skid.
Even after Coons' kick, the Beavers had one last chance to keep their perfect season alive. Starting at its 36 with 1:11 left, Vaz hit Richard Mullaney for 10 yards and Brandin Cooks for another 16 yards to the Washington 38 with 53 seconds left. Vaz misfired on his next two throws and on third-and-10 with 32 seconds left was sacked from behind by Talia Crichton.
A delay of game penalty backed up the Beavers again and on fourth-and-19 from the Washington 47, Vaz missed Kevin Cummings down the middle and Washington took over on downs.
"Very disappointing. Very hard. The key deal now is our reaction to it and where we go from here," Oregon State coach Mike Riley said. "It's just past the midway point. A lot of football left, so we'll just get back to work on Monday and I have a good sense these kids will come work very hard for next week's game."
Mannion never got into a rhythm. He was often late with his throws or threw behind receivers, and wasn't helped by the loss of star Markus Wheaton to a probable concussion in the second quarter on a pass that was knocked from Wheaton's hands and to Washington safety Justin Glenn for one of Mannion's four picks.
Mannion finished 18 of 34 for 221 yards and one touchdown, and the four interceptions tied a career high. Taking over for the final two drives of the game, Vaz was 7 of 11 for 97 yards. Storm Woods rushed for 90 yards before leaving late with a knee injury, and Cooks had nine catches for 123 yards and a 54-yard touchdown for Oregon State.
Riley said he never considered bringing on Vaz any earlier. Vaz had directed the previous two Oregon State victories while Mannion was recovering from surgery.
"I know that's their call to make. Would I have liked to have played? Obviously, but at the same time I know it's about the team and not about me for sure," Mannion said. "It's a bit disappointing but at the same time I'm behind Cody 110-perecent and you know, just try to support him any way I can."
Price, who committed 10 turnovers in the previous three games, started Washington's decisive drive hitting tight end Austin Seferian-Jenkins for 20 yards, just his third catch of the night. On third-and-7, Kasen Williams made a juggling catch along the sideline for 19 yards and an additional 15 yards was tacked on for a personal foul against Oregon State to move the ball to the Beavers' 18.
Price took an ill-advised sack on second down and couldn't connect with Sankey at the goal line on third down, but Coons was able to give the Huskies the lead.
Price finished 18 of 30 for 194 yards, but the game plan Sarkisian designed was meant not to put Price in the position of being pressured by Oregon State's defensive line. The Huskies ran the ball 20 times in the first half and 33 times total in the hopes of getting a lead and not playing catch up.
It worked as Washington took a 10-0 lead at the half thanks to a 1-yard TD run from Sankey on fourth down and Coons' 45-yard field goal. The halftime deficit was the first for Oregon State since late in the fourth quarter against Arizona on Sept. 29.
"I was surprised they were able to run. But I knew they were good running the ball," Oregon State defensive end Scott Crichton said. "But I just had a lot of confidence in our defense."