LAS VEGAS -- Chris Boucher is your basic matchup nightmare.

The Oregon senior is 6 feet 10, 190 pounds, with the long arms of an elite shot-blocker and the shooting touch of a wing.

He had it all on display eighth-ranked Oregon held off Washington 83-77 in the Pac-12 Tournament quarterfinals on Thursday.

Boucher had 19 points, including two 3-pointers, and 11 rebounds -- seven on the offensive glass. He blocked three shots.

"His two threes in the first half ... we were struggling," Oregon coach Dana Altman said. "We couldn't get anything going. His 3s in the first half got us going."

Boucher, a senior transfer in his first year of eligibility at Oregon, became the first player in Pac-12 history with 100 blocked shot and 30 made 3-pointers in a season. He posted his eighth double-double of the season.

"We just fed off Chris," Oregon forward Dillon Brooks said.

Top-seeded Oregon (26-6) advances to play fourth-seeded Arizona in the semifinals Friday at MGM Grand Garden Arena. Washington (17-14) is a good candidate for the NIT.

"At this point, I think we have to wait and see what happens on Sunday," Washington coach Lorenzo Romar said. "Regardless of the situation, I wouldn't think we're done playing basketball this year."

Oregon never trailed in the second half, led by 11 with 7:48 to go and then held on after Washington closed within two points three times, including 79-77 with 1:36 left on a dunk by forward Marquese Chriss.

Chriss had a chance to tie on the Huskies' next possession, but he missed a dunk in traffic. Oregon guard Tyler Dorsey, fouled after grabbing an offensive rebound on the ensuing possession, made both attempts with 32.2 seconds left for an 81-77 lead.

Chriss then missed a 3-point shot from the corner and Oregon forward Elgin Cook closed out the scoring with two free throws to finish with 19 points.

Dorsey finished with 17 points.

Oregon had 14 turnovers but a 46-33 advantage on the boards.

"They were a tough matchup for us, but I liked our effort," Altman said. "We had bad turnovers today. We didn't make very good decisions. We'll have to clean that up. But our effort on the boards, I think, was the difference in the game."

Boucher said, "At the end, we knew if we stayed together and all go to the rebound, we had a chance to win this game."

Chriss and guard Andrew Andrews each scored 19 points to lead five Washington players in double figures.

In a battle of athletic, up-tempo teams, Washington sprinted from the start, hitting 10 of 13 shots from the field for a 26-14 lead with 11:42 to go in the half.

Guard David Crisp came off the bench to hit a trio of 3-pointers during that span, and Chriss helped fuel the run with an alley-oop dunk, a spot-up 3-pointer from the corner, a blow-by for a dunk and a huge block at the rim.

"Washington came out and hit us pretty good," Altman said.

But the Huskies' shot selection became iffy, and the Ducks countered with its long, versatile forward. Boucher came to the rescue with 15 first-half points, including two 3-pointers, five offensive rebounds and a block that led to a fast-break layup by Brooks.

Oregon led 39-38 at halftime.

"When you lose your last game, you always come up short, regardless of how far you went," Romar said. "I know a lot of people didn't expect up to do what we did this year. ... In terms of our own expectations, we felt we could go a little bit further than we did."

NOTES: Washington broke the Pac-12 record for blocks in a season, which was 211, set by Arizona State in 2013-14. The Huskies swatted five shots from the Ducks to give them 215 for the season. ... Oregon won the only regular-season meeting between the teams, beating visiting Washington 86-73 on Feb. 28. ... Washington C Malik Dime did not have a block, so he remains tied for the season school record of 85 set last season by Robert Upshaw. ... Oregon All-Pac-12 F Dillon Brooks, the team's leading scorer at 16.7 points per game, picked up his second foul with 15:28 to go in the first half and sat for more than seven minutes. He finished with 15 points.