Brock Motum had 15 points and eight rebounds and Dexter Kernich-Drew added 10 points off the bench for Washington State (8-4) which has won six of its last seven. D.J. Shelton collected a game-high 11 rebounds.
Tony Watson scored a team-high 18 points off the bench for Buffalo (4-8) and Auraum Nuiriankh added 13 points and eight rebounds. The Bulls had won back- to-back games entering play.
Buffalo managed to get out to a 37-35 lead at the end of the first half by hitting 14-of-25 shots from the field including a 7-of-11 effort from beyond the arc. Washington State also knocked down 7-of-11 shots from 3-point range but hit just 12-of-26 overall.
The Bulls cooled off to just 6-of-29 shooting and made just 2-of-10 shots from beyond the arc in the second half. The Cougars were able to connect on 9-of-22 shots and outscored the Bulls 9-3 from the free throw line to earn the win.
Buffalo lost despite outrebounding Washington State (35-32). The Bulls committed nearly twice as many turnovers (13) as the Cougars (7).