Keeton completed 20 of 33 passes and Williams ran for 113 yards on 20 carries and caught seven passes for 147 yards for the Aggies, who are 4-1 for the first time since 1978. On the first play from scrimmage in the fourth quarter, Keeton hit Williams for a 74-yard touchdown pass to give Utah State a 27-13 lead.
Nick Sherry completed only 18 of 39 passes for 188 yards for the Rebels (1-4). His 3-yard scoring pass to Max Johnson in the second quarter was the first touchdown allowed by the Aggies in the first half this season.
Keeton was the first Utah State QB to pass for 400 yards since 2002.
Chuck Jacobs caught four passes for 101 yards and two touchdowns for Utah State.