Darius Ramsey's 20-yard TD run in the fourth quarter put the game out of reach for the Catamounts (6-2, 4-0 Southern).
Mitchell was 21 of 29 for 291 yards and two interceptions and gained 131 yards on 15 carries. Newsome gained 123 yards on 11 carries.
The Catamounts pulled ahead on Newsome's TD runs of 24 and 38 yards in the third quarter.
Miller ran for 104 yards on 22 carries and two scores, and his 27-yard TD in the fourth brought the Bulldogs to within six.
But the WCU defense forced a punt from its own 37 and Ramsey scored on the next drive.