Consecutive 3-pointers by Bobbitt and Jankovic gave Hawaii a 48-42 lead early in the second half. Jankovic extended the Rainbow Warriors' lead to 61-51, but Cal Poly rallied and Taylor Sutlive's 3-pointer pulled the Mustangs within 66-64 with seven minutes left.
Valdes finished with 20 points for Hawaii (12-2) and Fleming had 12 points with five assists.
Reese Morgan led Cal Poly (6-8) with 17 points.
Morgan scored eight of the Mustangs' final 10 points of the first half. Hawaii's Quincy Smith scored inside just before the halftime buzzer to tie it at 37-all.