Sumner completed 16 of 23 passes for 175 yards as the Jackrabbits (7-4, 4-3 Missouri Valley Football Conference) kept their playoff hopes alive with their third straight win. Sumner connected with Jason Schneider from 34 yards in the first quarter and 5 yards early in the fourth.
SDSU ran for 140 of its 315 total yards, while South Dakota (4-7, 3-4) was one-dimensional on the offensive end.
The Coyotes were held to just 59 yards rushing, leaving quarterback Kevin Earl to carry most of the offensive load. Earl completed just 21 of 48 passes, but went for 325 yards and a touchdown.
SDSU's Winston Wright returned an interception 85 yards with 2:36 to play for the final margin.