The Utes, seeded 10th in the conference tournament, finished the regular season 5-13 in league play, four games behind USC. DuBois was 7-of-12 from the field, leading a Utah team that only shot 38.6 from the floor in their first Pac-12 tournament win since moving to the league at the beginning of the 2011-12 season.
The Utes held a six-point lead headed into the last minute of the game, but USC closed it to 69-66 with 39 seconds left on a J.T. Terrell three-pointer. USC would not get the ball back.
Omar Oraby had 18 points (8-of-11 shooting) and 10 rebounds for the Trojans, who shot 3-of-15 from three-point range. Utah was 18-of-21 from the free throw line Wednesday.
Utah will play the No. 2 California Golden Bears in the quarterfinals Thursday. USC finished its season 14-18 under interim head coach Bob Cantu.