Washington pummeled OSU on the boards, out-rebounding the Beavers 40-28.
Washington committed 13 turnovers in the first half, but the Beavers built only a four-point lead. And OSU was in a giving mood themselves, with seven turnovers over the first 20 minutes.
Washington went on a 14-5 run in the first five minutes of the second half. After that, OSU then climbed back only to fall back the rest of the way.
Oregon State turned in a 7-for-29 shooting performance in the second half. But the Beavers were able to stay close through most of the game by hitting 19 of 27 free throws and taking advantage of UW's 19 turnovers.
Had the Beavs won, it would have been their first sweep over the Huskies in 10 years.
"It just felt like we were out of sorts," Robinson said. "I don't know if that had to do with staying here the whole time or if it was just a function of having beaten them the first game and thought you could just show up and play this time around. It really felt like we were out of sorts right from the beginning."
Roberto Nelson was only 3-16 from the field but sank 11-13 free throws to lead the Beavs with 19 points.
The Beavers return to Corvallis for their final home games of the season nest week -- Thursday (8 p.m.) against Stanford and Saturday against Cal (3 p.m.).