The Spartans opened the scoring when Jarius Jones intercepted a pass by Tyler Van Tubbergen at the 25-yard line, then tossed a lateral pass to Kurtis Drummond for a fancy first touchdown of the season for a 7-0 first-quarter lead.
The Broncos hung around, and the game was 7-7 nearing halftime. But a seven-play, 69-yard drive by Michigan State in the final minute of the second quarter capped by a 2-yard run by Jeremy Langford gave the Spartans a lead they never relinquished.
Andrew Maxwell and Connor Cook split the QB duties for the Spartans, Maxwell going 11-for-21 for 74 yards and Cook 6-for-16 for 42. Neither threw an interception, but neither threw a touchdown either as MSU struggled to keep its offense going against the MAC's Broncos. The Spartans' offense rolled up 181 yards on the ground, 94 by Langford.
Van Tubbergen split time with Zach Terrell for Western Michigan, but the duo combined to complete just 18 of 48 passes for 193 yards on the night, with two touchdowns and three interceptions.
Terrell fumbled in the fourth quarter, which was returned for a touchdown by Shilique Calhoun to give Michigan State its final score.
The Spartans won their 13th season opener in the last 15 seasons. Michigan State improved to 11-2 all-time against WMU, including 8-0 at home against the Broncos.
Michigan State next hosts South Florida on Sept. 7. Western Michigan has its home opener next week, hosting Nicholls State on Sept. 7.