With their seventh consecutive victory, the Bruins improved to 9-1, winning their first Pac-10 match of the season. The Cats dropped to 8-3, 2-1 in the league.
Arizona was led by junior middle blocker Marisa DaLee, who hit .522 (14-2-23), and sophomore setter Dana Burkholder, who added 37 assists and a match-high three blocks.
The Cats return to action Saturday evening when they face No. 18 Southern California (6-2, 1-0) in Los Angeles at 7 p.m. PDT. Arizona returns home next Friday, Oct. 1, when it plays host to cross-state rival Arizona State at 7 p.m.