Sama Taku added 13 points and went 10 for 10 from the free-throw line for the Tigers (15-10, 9-4 Big West), who took sole possession of second in the conference standings.
Hawaii led 38-33 in the second half before it went scoreless for a 6:17 stretch, enabling Pacific to take control of the game with a 15-0 run. Tony Gill had all of his five points during the stretch, and Fulton and McCloud added four points each.
The Warriors got no closer than seven points the rest of the way.
Dillon Brooks, who led Oregon with 16.7 points per game last season, will opt out of the NBA draft process and return to the Ducks, a source told ESPN.
Mississippi State freshman guard Malik Newman will withdraw from the NBA draft, but sources told ESPN he might explore other opportunities besides returning to Mississippi State.
Seton Hall sophomore Isaiah Whitehead will stay in the NBA draft and not return for his junior season.