Josh Swogger settled down after he threw his first collegiate touchdown pass.
Swogger, who took the majority of snaps in practices, replaced starter Matt Kegel in the second quarter with the score tied, 10-10, and led two long scoring drives.
The extra practice paid off, and Swogger said he felt comfortable against Arizona State's defense. "The learning process is coming along really well," Swogger said of his quick education in running a team.
The Cougars, who improved to 9-2 overall and 6-1 in the conference, could record their third consecutive 10-win season with a victory next week over Washington in Seattle. The Sun Devils (4-7, 1-6) are heading to their second losing season in three years under Coach Dirk Koetter.
Washington State rolled up 402 yards of offense, while the Sun Devils had 322.
Swogger hit Devard Darling in the end zone on a 22-yard pass to make it 24-10 just before halftime. Swogger completed 14 of 20 passes for 207 yards and a touchdown.
Kegel, who reinjured his right throwing shoulder last week against UCLA and practiced sparingly all week, was five for 11 for 77 yards and an interception.
Arizona State's Andrew Walter threw a 25-yard scoring pass to Derek Hagan, but the Sun Devils were held in check by the Washington State defense, which had three sacks and forced three fumbles. Walter completed 19 of 35 for 262 yards and an interception.
Washington State kicker Drew Dunning connected on a 32-yard field goal in the third quarter to break Jason Hanson's school record of 64 field goals. Dunning tied the record with a 31-yarder in the first quarter that put the Cougars ahead, 10-7.
"That's quite an accomplishment for Drew," Coach Bill Doba said.
Oregon State 43, Stanford 3 -- Derek Anderson passed for 383 yards and four touchdowns and Mike Hass had eight catches for 225 yards and two scores, leading the Beavers (7-3, 4-2) over the Cardinal (4-5, 2-5) at Corvallis, Ore.
Steven Jackson, who leads the Pac-10 in rushing, ran for 148 yards in 21 carries and a touchdown in a nearly constant drizzle.