Devon Collier had 23 points as Oregon State overcame a listless first half to defeat the Vikings 79-74 on Wednesday night.
Joe Burton added 20 points and seven rebounds for the Beavers (6-2), who became the first Pac-12 team to play at the 1,500-seat Peter W. Stott Center on the Vikings' downtown Portland campus.
The Beavers trailed for most of the first half before pulling away to lead by as many as 14 points in the second — and holding off a late rally that got the Vikings within five points.
The Vikings (1-5) have lost five straight after winning their opener against the Pacific (Ore.) Boxers back on Nov. 9. Portland's losses before the Beavers all came on the road.
The Beavers have won four of their last five games, including last Saturday's 85-54 victory over Grambling State. Their lone loss in the stretch was at then-No. 10 Kansas, 84-78.