EUGENE, Ore. -- A dominant first half was enough to give Oregon the outcome it was looking for in its rematch with Oregon State.
It also let the Ducks avoid their first Civil War sweep by the Beavers in eight years.
Brown had 18 points in the first half as the Ducks (14-7, 4-4 Pac-12) built a 41-25 lead. Oregon held the Beavers (11-9, 3-5) scoreless for more than 6 minutes during a 22-2 run.
"It was a combination of our guys not running offense the way we're supposed to and then the job they did defensively," Oregon State coach Wayne Tinkle said. "Got to give them credit."
The Beavers won the first meeting 76-64 in Corvallis three weeks ago, but their early 9-5 lead evaporated quickly this time. The Ducks were 14 of 20 from the field with 3 minutes left in the half and had forced nine turnovers, which led to 17 points.
"The biggest difference was our activity defensively," Oregon coach Dana Altman said. "I thought defensively we really flew around, and we had some good possessions.
"We got kicked in Corvallis and didn't play very well. . We have played better since that game."
Brown, the Ducks' second-leading scorer at 13.2 points per game, made three 3-pointers in the first half to go with seven free throws. The Pac-12 leader at the foul line made all nine of his free throws and has made 39 straight since his last miss 15 games ago.
Brown now is 50 of 52 (96.3 percent) on the season.
"He gives us another gear when he's shooting it," Altman said. "When he's shooting it good, it definitely gives us a big dimension offensively."
Stephen Thompson Jr. led Oregon State with 16 points. Tres Tinkle scored 13 and Ethan Thomson had 11.
The Beavers were just 3 of 17 beyond the arc and missed all eight attempts in the second half. They finished with a 32-28 edge in points in the paint and had 11 second-chance points to none for the Ducks.
However, White led Oregon to a 21-7 margin in bench points.
"We've got to where our guys, our stars, they've got to bring it," Tinkle said, "and then we've got to get some points off the bench. We had shooters passing up open looks, so we were a little bit tentative."
The Ducks never let their lead get below eight points despite shooting just 6 of 24 (25 percent) in the second half. The conference leaders in free-throw accuracy at 79 percent made up for it by going 19 of 24 from the foul line.
"We got real stagnant offensively," Altman said. "We never really got that rhythm offensively we had in the first half."
Drew Eubanks had nine rebounds for the Beavers but only four points, nearly nine off his season average. Both teams finished with 28 rebounds.
Payton Pritchard had seven points and seven assists for Oregon.
Oregon State has lost four of its last five heading to the Bay Area and is 10th in Pac-12 at 3-5. The Beavers won at Stanford two seasons ago but haven't beaten California on the road since 2009.
Oregon plays six of its last 10 games on the road, starting with a trip to Stanford and California. The Ducks have been strong finishers under Altman, going 30-6 over the second half of the last four Pac-12 seasons.
Oregon State: Plays at Stanford on Thursday night.
Oregon: Plays at California on Thursday night.
Oregon pushed its lead to 15 points midway through the second half on a tomahawk dunk by Kenny Wooten off Troy Brown's dribble penetration and Pritchard's driving layup high off the backboard and free throw.
STAT OF THE NIGHT
Oregon led by as many as 21 in the first half without two of its top scorers, Pritchard and MiKyle McIntosh, contributing a point. Pritchard averages 10.9 shots per game but didn't attempt his first until the last 3 seconds of the first half
HE SAID IT
Wayne Tinkle didn't like the way his team responded to the Ducks' pressure or the sellout crowd of 12,364 in the first half. "I don't know if it was the environment," he said. "We said we need to be the aggressor like we were in the first game, and we weren't. We were a little too cool for school there for a while and we had to get after some guys, and then we didn't make shots."
Mannion, who recently reclassified and is ESPN's No.11 overall player in the class of 2019, chose Arizona over Marquette.
He'll fit in with Sean Miller's plans for a faster tempo on offense.
The cream of the crop of American high school basketball will congregate in Colorado Springs from Oct. 5-7, as USA Basketball unveils its newly expanded Junior National Team minicamp in collaboration with the NBA, NCAA and NBPA.