Michael Flowers poured in 27 points, Mouhamed Gueye scored eight of his 19 in overtime and Washington State handed Oregon State its 15th straight loss 103-97 on Monday night.
Flowers sank 10 of 18 shots from the floor, including 6 of 10 from 3-point range, for the Cougars (16-13, 9-9 Pac-12 Conference), who trailed 48-37 at halftime. He added six assists and five rebounds.
Washington State grabbed its first lead since midway through the first half, 72-71, on a Flowers 3-pointer with 6:30 remaining. Dashawn Davis and Dexter Akanno sank 3s on Oregon State's next two possessions and the Beavers (3-25, 1-17) stayed in front until Tyrell Roberts hit the first of two free throws for WSU with 15 seconds left to send the game to OT tied at 84.
Gueye scored on a layup off the OT tip, then hit two free throws following an Oregon State turnover to put the Cougars up 88-84 just 45 seconds in. The Beavers pulled within 91-90 with 2:22 to go on a bucket by Davis. TJ Bamba scored with 1:56 left coming out of a WSU timeout, Flowers buried a 3-pointer after another Beavers turnover and the Cougars maintained a two-possession lead from there.
Roberts finished with 12 points for the Cougars, who beat the Beavers in Corvallis for the first time since 2013. Bamba and Noah Willaims added 11 points apiece and Dishon Jackson had 10 points and six rebounds off the bench.
Roman Silva scored 15 of his 21 points in the first half and added seven rebounds for Oregon State. Jarod Lucas had 20 points and Maurice Calloo scored 17 — 15 in the first half. Davis pitched in with 13 points and 11 assists, while Glenn Taylor Jr. totaled 10 points and seven boards.
Washington State returns home for the final two regular-season games — hosting Oregon State on Thursday and Oregon on Saturday. Oregon State closes out its regular season at Washington on Saturday.