Oregon unleashed another stifling defensive performance, winning its season-high fifth consecutive game by overpowering Washington State 84-51 Wednesday night in the first round of the Pac-12 tournament in Las Vegas.

Seven Ducks scored at least seven points -- led by Ehab Amin off the bench with 17 -- but defense set the tone from the start. Oregon's length and pressure were problematic for Washington State, which committed 16 first-half turnovers and fell behind by as many as 35 points in the second half.

Sixth-seeded Oregon will play third-seeded Utah in a quarterfinal game Thursday night at T-Mobile Arena.

The Ducks (20-12) have allowed an average of 51.4 points in their five-game winning streak. They held the Cougars to 30.8 percent shooting (16 of 52), including 7 of 32 from 3-point range.

Oregon has held five consecutive opponents below 62 points for the first time since the 1984-85 season.

Miles Norris scored 14 for Oregon, while Louis King had 12 and Will Richardson added 10.

Oregon stifled Washington State's Robert Franks, who entered the tournament leading the conference at 22.1 points per game. He didn't score until there was 5:34 left in the first half, and he finished with eight points on 2-of-9 shooting.

Marvin Cannon and CJ Elleby each put in nine points to lead the Cougars.

Washington State (11-21) made the first basket of the game, a 3-pointer by Elleby -- and then it was all Ducks.

Oregon ran off the next 18 points, held the Cougars scoreless for more than nine minutes and forced 13 turnovers in less than 13 minutes. Washington State made only one of its first 12 shots.

The Ducks led by as many as 21 in the first half and were up 37-20 at the break. They erased any doubt by scoring the first nine points of the second half, capped by a 3-pointer by Paul White.

Oregon junior point guard Payton Pritchard had three steals to push his career total to 156, putting him into third place on the school's career list.

Oregon reached the 20-win level for the ninth consecutive season, all under coach Dana Altman.

--Field Level Media