Askia Booker scored 21 points and keyed a late run, leading Colorado to a 59-56 win over scrappy Southern California in the opening round of the Pac-12 tournament on Wednesday.
Their NCAA tournament hopes still up in the air, the Buffaloes could not afford a loss to the last-place Trojans.
Despite beating USC twice during the regular season, Colorado (22-10) had a hard time shaking the Trojans, unable to get much separation until going on a 13-1 run late in the second half.
USC (11-21) still had a shot at the end, but Byron Wesley's 3-pointer at the buzzer came up just short.
Josh Scott had 13 points and Xavier Johnson added 11 for the Buffaloes, who move on to face California in Thursday's quarterfinals.
Wesley finished with 23 points for the Trojans, who kept it close despite going 5 of 22 from 3-point range.