After Hill was intercepted on BYU's next possession, the Cougars grabbed a 14-0 lead early in the second quarter on a 22-yard touchdown pass to Ross Apo.
In the face of an all-out blitz by Hawaii's defense, Hill calmly dumped the ball to Apo, who was wide open over the middle. He easily raced into the end zone for his first touchdown of the season.
With 6:16 left in the half, BYU extended its lead to 20-0. Hill broke across the line of scrimmage and accelerated away from the defense on a 68-yard touchdown run.
In the third quarter, it took BYU only 1:22 to extend its lead.
After recovering a Hawaii fumble inside the five, Williams scored on a three-yard run to put the Cougars in front, 27-0, and end the Warriors' faint comeback hopes.
Williams, who rushed for 86 yards in BYU's first four games, gained 155 yards on 15 carries against Hawaii.
The game was delayed twice in the first quarter because of injuries to Hawaii players.
Senior nose tackle Geordon Hanohano and junior defensive tackle Siasau Matagiese were taken from the field on stretchers and left the stadium in an ambulance. Neck X-rays taken at the hospital were negative.