SPOKANE (AP) - Washington State wasn't too worried about Oregon's Olu Ashaolu going into Thursday's game. The Cougars should have been.

Ashaolu, a transfer from Louisiana Tech, scored 23 points and grabbed 10 rebounds as the hot-shooting Ducks beat Washington State 92-75 in the Pac-12 Conference opener for both teams.

Ashaolu, who was 9 of 11 from the field, said the difference in this game was moving down low after spending more time on the perimeter in previous games.

"That's what I call home on the basketball court," Ashaolu said.

Oregon shot 69 percent from the field and never trailed in blowing out the Cougars.

Devoe Joseph added 17 points for Oregon (10-3), which won its fourth straight game. E.J. Singler added 13 points and Garrett Sim had 12 for the Ducks.

DaVonte Lacy scored 19 points for Washington State (8-5), which shot 46 percent from the field and saw a six-game winning streak snapped.

Washington State fell behind by 20 at halftime as Oregon shot 71 percent in the first half.

"We are better than that," Cougars coach Ken Bone said. "We know it. Our guys know it."

But Oregon's fast start and hot shooting left the Cougars frustrated, he said.

"That first half, they put on a clinic on offense," Bone said.

"There were times when there was no real (defensive) pressure," he added. "We were not scoring at a very good rate and that translated into poor defense."

Bone said he expected more trouble from Oregon's guards, who lead the team in scoring.

For the game, Oregon was 34 of 49 from the field, including 9 of 16 on 3-pointers. The Ducks outrebounded the Cougars 34-22.

Joseph scored three consecutive baskets as Oregon built a 71-50 lead midway through the second half. At that point the Ducks were shooting 72 percent for the game. The Cougars could not get within single digits the rest of the way.

Washington State hosts Oregon State on Saturday in Spokane.

OREGON (10-3)

Singler 5-10 2-2 13, Woods 2-3 0-1 4, Sim 4-4 3-4 12, Loyd 2-4 0-0 4, Joseph 6-9 2-2 17, Lucenti 0-0 0-0 0, Ashaolu 9-11 5-12 23, Kingma 3-4 0-0 9, Jacob 1-2 0-0 2, Emory 2-2 3-4 8. Totals 34-49 15-25 92.

WASHINGTON ST. (8-5)

Motum 3-8 6-7 12, Enquist 0-0 0-0 0, Capers 2-4 0-0 4, Moore 4-12 5-6 14, Lacy 7-9 0-2 19, Ladd 1-2 2-4 4, DiIorio 0-0 0-0 0, Aden 2-10 0-0 4, Shelton 3-4 1-1 7, Lodwick 2-5 0-0 6, Kernich-Drew 1-2 0-0 2, Simon 1-1 0-0 3. Totals 26-57 14-20 75.

Halftime_Oregon 54-34. 3-Point Goals_Oregon 9-16 (Joseph 3-4, Kingma 3-4, Sim 1-1, Emory 1-1, Singler 1-5, Loyd 0-1), Washington St. 9-21 (Lacy 5-6, Lodwick 2-5, Simon 1-1, Moore 1-3, Ladd 0-1, Kernich-Drew 0-1, Aden 0-2, Motum 0-2). Fouled Out_Capers, Lacy. Rebounds_Oregon 34 (Ashaolu 10), Washington St. 22 (Motum 5). Assists_Oregon 20 (Joseph 7), Washington St. 18 (Ladd, Moore 4). Total Fouls_Oregon 22, Washington St. 22. A_9,889.