The Beavers went 25-36 from the free-throw line.
DaVonté Lacy scored 18 and D.J. Shelton had a double-double (11 pts, 10 reb.) in the loss -- his twelfth of the season.
But it was two unlikely offensive sources who kept WSU in the game at times -- Junior Longrus and Brett Boese.
After the Cougs had fallen behind by 11 in the first half, Longrus' mid-to-long range jumpers as the Cougs trimmed the halftime deficit to 30-26. He finished 3-4 on the night in coming off the bench. Starting center Jordan Railey played 18 minutes to Longrus' 20.
After WSU fell behind by double-digits again in the second half, connecting on only three of their first 10 shots after halftime, Ken Bone subbed little-used Brett Boese into the game. The freshman responded with a three to cut the lead to 50-45 with 7:12 to play.
But WSU could draw no closer than that the rest of the way.
Lacy was just 4-12 from the floor, with nine of his points coming from the free throw line. Que Johnson played only 16 minutes in the loss, as Ken Bone tried in vain to find a combination that worked. The Cougs (43 percent) actually outshot the Beavs from the floor (42 percent) but the free throws disparity and six more shot attempts by OSU turned out to be the difference.
The Beav bench outscored WSU 20-11.