Missouri State (18-7, 9-5 Missouri Valley Conference) had a 37-25 halftime lead and pushed it to 49-32 with 14:43 left on a 3-pointer by Spencer Laurie. But Illinois State (12-13, 4-1), which led briefly in the first half, went on a 10-0 run to cut Missouri State's lead to 49-42 with 10:58 left.
Ahearn and Tyler Chaney scored six of the next eight Missouri State points to put the Bears up 57-42 with 8:41 left. Two Ahearn free throws with 4:17 left gave Missouri State a 66-50 lead, and the Bears kept the lead the rest of the way.
Missouri State outrebounded Illinois State 50-25. The Redbirds had just two offensive rebounds.
Chaney finished with 13 points, Drew Richards added 11 and Laurie had 10 for Missouri State.