Busch has six straight series victories dating to last season and 40 overall. The Sprint Cup driver led the final 55 laps in the 150-lap race. He also won at 1.5-mile track in 2011.
Wallace, the winner two weeks ago at Gateway in Madison, Illinois, finished 1.844 seconds behind Busch.
Ryan Blaney was third, followed by Timothy Peters, Brad Keselowski, Matt Crafton, Austin Dillon, Ron Hornaday Jr., points leader Johnny Sauter and Ben Kennedy.
Sauter has an eight-point lead over ThorSport Racing teammate Crafton, the defending series champion and a two-time winner this season.