The Warriors made 9 of 20 3-pointers compared to 3-of-18 shooting for UC Riverside. The Highlanders were 0 of 9 from distance in the second half.
Hawaii (17-9, 5-5 Big West Conference) improved to 9-0 this season following a loss.
Roderick Bobbitt had four steals to set Hawaii's single-season record at 85.
Riverside made its first three shots to open an 8-4 lead with 18:13 left, but Steven Thornton's 3-pointer at the 3:23 mark was the Highlanders' next field goal. Hawaii had a 35-20 edge after the 15-minute field-goal drought and led 42-28 at the break.
Hawaii led by as many as 24 points.