Mariah Cooks had 16 points for the Cougars (6-13, 2-6 Pac-12), who trailed 38-24 at halftime. Washington State used a 17-2 run starting the second half to go in front 41-40 with 14 minutes to play. Neither team led by more than four points for the rest of regulation, and the Cougars never led by more than four at any time in the game.
In overtime, Oregon State built a 73-67 lead, but the Cougars scored the last nine points with Dawnyelle Awa's free throws with 30 seconds left putting them ahead 74-73.
Ali Gibson led the Beavers (9-11, 3-5) with 18 points. Alyssa Martin scored 17 points, Jamie Weisner added 16 points and Samantha Siegner had 10 points, eight rebounds and five blocks.