Freshman forward Tres Tinkle came off the bench to post 19 points and six rebounds, helping Oregon State hold off rival Oregon 70-57 in a Pac-12 Conference opener Sunday at Gill Coliseum in Corvallis, Ore.

Senior forward Olaf Schaftenaar had 13 points and eight rebounds for Oregon State (10-2, 1-0 Pac-12). Senior guard Langston Morris-Walker added 12 points and six rebounds, and senior guard Gary Payton II had 12 points, six rebounds and six assists.

Junior forward Chris Boucher had 14 points and seven rebounds to lead Oregon (11-3, 0-1). Sophomore forward Dillon Brooks scored 13 points, and freshman guard Tyler Dorsey had 10.

Oregon State outscored Oregon 9-3 over the first five minutes and took an 18-10 lead on a 3-pointer by freshman guard Stephen Thompson Jr. A short time later, the Beavers mounted an 11-2 run to extend their lead to 16.

Oregon State led 34-19 at the break and went up by 18 early in the second half. Oregon used a 12-3 run to cut the deficit to single digits, but baskets by Payton and freshman forward Drew Eubanks helped the Beavers regain control.

The Ducks made one last charge to get within eight with 3:27 remaining, but they couldn't get any closer.