CORVALLIS, Ore. -- Mac Hopson's jumper with 35.5 seconds to go put Washington State ahead for good and the No. 9 Cougars held off Oregon State 58-54 on Saturday night.

AP

Washington State guard Mac Hopson, a Portland native, drives to the hoop against Oregon State guard Josh Tarver. Hopson sank a jump-shot with 35.5 seconds to go to put Washington State in the lead for good to beat Oregon State, 58-54.

Washington State (23-5, 12-4 Pac-10) was coming off a 64-59 loss to No. 23 Oregon on Thursday. The loss slimmed the Cougars' chances of catching UCLA in the conference race.

The No. 4 Bruins clinched at least a share of the Pac-10 after Saturday's 75-61 victory over Stanford put them at 14-2. The Cougars host UCLA on Thursday, before closing out the regular season on Saturday against USC.

Washington State, which trailed by as many as eight points in the second half, pulled ahead when Aron Baynes scored eight straight points to give the Cougars a 47-45 lead.

The Beavers stayed in the game, and tied it at 54 on Wesley Washington's layup with 1:02 left. The Cougars took back the lead on Hopson's jumper.

After Oregon State's Josh Tarver missed a 3-point attempt, Baynes made a pair of free throws with 8.7 seconds left.

Baynes led the Cougars with 14 points.

Oregon State (11-19, 3-14) was coming off a 73-65 victory over Washington on Thursday. The Beavers' only conference victories have come against the Huskies and Arizona State.

Marcel Jones had 16 points for the Beavers, who had won eight straight against the Cougars at Gill Coliseum. The 273 meetings between the two teams are the fourth-most between a pair of teams in NCAA Division I.

The Beavers took an early 10-3 lead on Tarver's 3-pointer and kept it for much of the first half. The Cougars narrowed it to 24-23 on Robbie Cowgill's layup.

After Kyle Jeffers made one of two free throws, Washington State's Ivory Clark tied it at 25 with a jumper.

But the Cougars could not get the lead, and Jones' layup extended the Beavers' advantage to 32-27 at the break. Jones led all scorers with 12 points at the half.

Tarver's layup early in the second put the Beavers ahead 37-29, their biggest lead of the game so far.

After trailing 45-38 midway through the second half, the Cougars tied it at 45 when Baynes hit three straight baskets and added a free throw. He added two more free throws to give Washington State its first lead of the game.

The last Cougar win at Gill was 1998. Washington State defeated the Beavers 70-55 earlier this season in Pullman.