The Cougars (9-4) used a 20-2 run late in the first half to blow open a close game.
Point guard Mike Ladd scored 17 points and grabbed nine rebounds to lead the Cougars, who have won four in a row and six of their last seven games.
Brock Motum added 17 points and seven rebounds for Washington State, which trailed 8-6 midway through the first half before Ladd scored seven points and Motum five during the run which put the Cougars on top 26-10 with 4:37 left in the half.
- Did Rasheed Wallace poke fun at Roy Williams with red hoodie?
- Iowa big man Adam Woodbury silences critics
- No. 6 Kansas beats No. 10 West Virginia, 75-65
- Villanova cruises by DePaul 86-59 in 1st game as No. 1 team
- Late basket helps No. 12 Miami edge Pittsburgh 65-63
- No. 22 Kentucky has it easy against Georgia in an 82-48 rout