Brock Motum had 24 points and nine rebounds to lead Washington State to an 83-73 win against Oregon State on Thursday night.
D.J. Shelton added 14 points for the Cougars (13-11, 5-7 Pac-12), who had lost three of their previous four games.
Jared Cunningham had 33 points and six rebounds for Oregon State (15-9, 5-7).
Washington State led by 15 points at halftime, and stretched the margin to 59-41 on consecutive baskets, the second by Shelton off a steal with 13:15 left.
The Beavers got as close as nine in the closing minutes.
Washington State shot 28 of 54 from the field, while Oregon State was 22 of 59.