LAS VEGAS - Spencer Dinwiddie scored 20 points and Colorado picked up a much-needed win at the Pac-12 tournament, holding off Oregon State 74-68 in the first round Wednesday.
Colorado (21-10) needed a couple of wins in Las Vegas to boost its NCAA chances and got off to a good start by dominating Oregon State defensively most of the second half.
Xavier Johnson had 16 points and Andre Roberson 12 for the fifth-seeded Buffaloes, who moved on to face No. 4 seed Arizona in Thursday's quarterfinals.
Oregon State (14-18), the No. 12 seed, pulled off one of the biggest upsets in Pac-12 tournament history by knocking off top-seeded Washington last year and dimmed Colorado's NCAA hopes with a win in Boulder last weekend.
The Beavers fell short of repeating either performance by struggling against Colorado's defense, hitting 7 of 25 from 3-point range.