Lathen Wallace's 3-pointer with 1.1 seconds left gave Oregon State at 67-64 victory over Arizona on Thursday night.
Roeland Schaftenaar had 22 points for the Beavers (8-8, 2-2 Pac-10), who trailed by as many as 11 in the second half after leading by 13 in the first half.
Derrick Williams had 20 points for the Wildcats (8-9, 2-3).
Oregon State outscored Arizona 21-7 after the Wildcats had taken a 57-46 lead on Brendon Lavender's 3-pointer with 8:57 remaining.
After Oregon State forced Arizona into a shot clock violation with 14 seconds left, Calvin Haynes found Wallace alone in the corner for the game-winning shot.