Gary Payton II had 22 points, 15 rebounds, eight assists and four steals, leading Oregon State over No. 21 USC, 85-70, Sunday.
Tres Tinkle added 18 points and Drew Eubanks had 12 points and three blocks as the Beavers (12-6, 3-4 Pac-12) broke a three-game losing streak.
Elijah Stewart had 16 points and nine rebounds and Katin Reinhardt scored 14 points for the Trojans (15-5, 4-3), who lost both games on their Oregon road trip.
The Trojans led 40-36 at the break. Oregon State scored the first seven points of the second half, and a twisting lay-in by Payton gave the Beavers a 43-40 lead at the 18:45 mark.