Oregon State Coach Wayne Tinkle said his team "drew a line in the sand" during a timeout with about three minutes left against UCLA, with the Beavers having blown nearly all of a 17-point lead.
"We came too far to give it up. We don't lose the last four minutes at home," he added.
Gary Payton II had 18 points and five steals as Oregon State held off a furious UCLA second-half rally to win, 66-55, Thursday night.
Malcolm Duvivier added 19 points for the Beavers, (13-5, 4-2 Pac-12), who are undefeated at home this season in 11 games.
Bryce Alford scored 18 and Norman Powell added 13 and 10 rebounds for the Bruins (11-8, 3-3), who had won three in a row.
"It's going to be hard winning in someone else's building shooting 30%," UCLA Coach Steve Alford said.
Alford made five of 15 shots, Powell made five of 18 and Isaac Hamilton was 0 for 10.
UCLA made two of 17 field goals in the first 10 minutes of the game, but Oregon State only led 13-6 before a 7-0 run by the Bruins tied it.
Payton scored 11 consecutive Oregon State points to give the Beavers a 24-15 lead with 3:06 left in the half.
"He dominated the game every way you could do it," Steve Alford said.
Oregon State had a 47-30 lead with 9:28 remaining before UCLA roared back with a 20-5 run to cut the lead to 52-50.