Arizona played aggressive man-to-man and was better with help defense after struggling against the Beavers in the earlier meeting -- Oregon State in 17 turnovers -- 12 of those on steals -- in the rematch.
Oregon State (14-7, 5-4) handed Arizona its only conference loss earlier this month by attacking its defense. The Beavers were the ones on their heels on Friday, unable to get anything to fall inside or out against the Wildcats' pressure.
The Beavers shot just 28 percent from the floor, with leading scorer Gary Payton II held to six points on 3-of-13 shooting.
Oregon State went 3-for-15 from 3-point range, and Payton, who averages 13.2 points per game, never seemed comfortable against Arizona's attacking defense.
Olaf Schaftenaar led the Beavers with eight points.
"They had a lot of possessions and they got a lot of deflections," Oregon State coach Wayne Tinkle told the Associated Press. "I think that caused a lot of frustration for some of our guys."
The Beavers pulled off the upset of the Pac-12 season so far, knocking off Arizona 58-56 on Jan. 11 for their first win over a top-10 team in 15 years.
The Beavers managed to keep Friday's game at their pace for most of the first half, working the shot clock down to keep it close. But the Wildcats shifted the tide late in the half behind their defense, holding Oregon State scoreless over the final 7:45.
The Beavers hit six of 20 shots in the first half, including going 1-for-8 from 3-point range. The Beavers also had 11 turnovers.
Arizona scored the final 11 points of the half to lead 24-13. After a brief 4-0 run to start the second half, Arizona pulled away. Arizona missed its first nine shots, while Oregon State opened 1-for-8.
The Beavers struggled against Arizona's pressure, finishing 8-for-29 in the second half to spoil any chance of a comeback.
"Arizona is really aggressive, which pushed us into taking shots we're not comfortable with," Oregon State guard Malcolm Duvivier said. "We couldn't get the ball in the rim tonight even though we were getting people in positions to score."
UP NEXT: Oregon State hosts Washington State on Thursday. The Beavs won the earlier meeting against the Cougs in Pullman.