Drew Eubanks had 19 points and Stephen Thompson Jr. had 14 for the Beavers (16-15), who avenged a two-point home loss to the Huskies last Thursday and have won three of their last four.
Matisse Thybulle had 16 points, Noah Dickerson had 15 points and 10 rebounds before fouling out in overtime and David Crisp had 13 for the Huskies (20-12), who have lost their last two and appear out of the running for an NCAA tournament bid.
With the game tied, Tinkle was fouled as he attempted a baseline jumper with the shot clock running down. His foul shots made it 66-64 lead with 21 seconds remaining.
Crisp threw a pass out of bounds with 11.4 seconds left and Eubanks made the second of two free throws with 10 seconds remaining to make it 67-64 lead.
Crisp eschewed a potential tying 3-pointer for a driving layup with 3.1 left.
Tinkle made two free throws after being fouled on the inbounds pass left. Crisp's 40-foot 3-point attempt bounded off the back rim as time expired.
Oregon State will meet USC in the quarterfinals on Thursday. The Beavers lost both regular-season games to the Trojans by a combined 20 points.
Tinkle extended his streak of scoring in double digits to 34 games, although it took him overtime to get there. He was the only player in the Pac-12 to finish the regular season in the top 10 in scoring, rebounding, assists and steals.
Thybulle gave the Huskies a 64-63 lead on a 3-pointer with 1:49 remaining in overtime before the Beavers made six of eight free throws down the stretch.
Eubanks hit two free throws with 33 seconds remaining in regulation to send the game into overtime.
--Field Level Media
Oregon St. | Washington | |
Drew Eubanks 19 | Scoring | Matisse Thybulle 16 |
Ethan Thompson 4 | Assists | David Crisp 3 |
Tres Tinkle 10 | Rebounds | Noah Dickerson 10 |
Tres Tinkle 6 | Free Throws Made | Noah Dickerson 9 |
Stephen Thompson Jr. 2 | Steals | Noah Dickerson 2 |
Drew Eubanks 1 | Blocks | Noah Dickerson 2 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Oregon St. | 69 | 39.3 | 5-22 | 20-32 | 12 | 39 | 2 | 4 | 10 |
Washington | 66 | 38.3 | 6-21 | 14-18 | 9 | 32 | 6 | 5 | 11 |