Oregon State pulled away midway through the second half when Gibson hit a pair of 3-pointers and Sydney Wiese added a third, turning a five-point lead into a 12-point advantage with less than five minutes to play.
OSU played at home for just the fourth time over the past two months, having played six road games and five on neutral courts.
Wiese, a freshman point guard, finished with 13 points and dished out six assists. Ruth Hamblin and Jamie Weisner both added 12 points. Oregon State (11-8, 3-4 Pac-12) shot 26-of-61 from the field (42.6 percent) and converted 11 of 25 3-point attempts.
Washington (10-8, 3-4) got 27 points from Kelsey Plum and another 21 from Jazmine Davis, but shot just 36.9 percent (24-of-65).
More Sports Headlines
Huskies' Tupou overcame many obstacles en route to starting role Patriots acquire LB Jonathan Bostic from Bears 10:54 a.m. Larry Brown suspended by NCAA; SMU gets postseason ban 10:53 a.m. Seahawks’ Lynch has MRI on injured hamstring Mariners hire Jerry Dipoto as general manager Astros win 3-2, hand Mariners sixth straight loss Nats suspend Papelbon 4 games for fight with Harper Steelers' Roethlisberger will miss ‘a number of weeks’
Our new comment system is not supported in IE 7. Please upgrade your browser here.