Michael Wright scored 22 for Arizona, most long after the outcome was decided. Gilbert Arenas and Rick Anderson added 13 points apiece and Luke Walton had 12 points and eight assists.
Oregon State struggled against Arizona's quick defense, committing 20 turnovers, 10 by point guard Deaundra Tanner, who also made just two of 10 shots.
Brian Jackson led Oregon State with 18 points and Justin Heide and Jimmie Haywood added 12 apiece. All of Heide's points came in the second half. Haywood was 4-for-4 from 3-point range.
Up 40-30 at the break, the Wildcats scored the first 12 points of the second half to blow out to a 52-30 lead. Arenas scored six during the spurt. Meanwhile, the Beavers committed five turnovers in the first 4 1/2 minutes of the second half.
Oregon State didn't come closer than 15 again.