Bo Barnes added 14 points and Josten Thomas had 12 points and a game-high nine rebounds for Hawaii (4-0).
Mike Pouncy's 3-pointer gave Central Arkansas a 20-15 lead midway through the first half. But the Rainbow Warriors outscored the Bears 31-10 over the rest of the half, including three 3-pointers by Barnes.
Trevor Wiseman's basket with 14:48 remaining gave Hawaii its largest lead at 60-37. Central Arkansas got as close as 78-69 with 51 seconds left after a steal and layup by Williams.