A bruised shoulder didn't seem to slow down Mallett, who found Jarius Wright on a pair of scores while completing 27-of-44 passes for the Razorbacks (6-2, 3-2 SEC).
Wright hauled down six receptions for 88 yards for Arkansas.
The Razorbacks' 556-yard ground attack was keyed by Knile Davis, who rushed for 81 yards and two touchdowns on 19 carries.
The Commodores (2-6, 1-4) were shut down offensively. Quarterback Larry Smith threw just 12 times, completing four passes for 25 yards.