The Redbirds (8-3) led 74-67 with 1:59 to go, but the Flyers scored six straight points, capped by Devin Oliver’s layup with 35 seconds left.
After Illinois State’s Johnny Hill missed a free throw with 29 seconds remaining, Dayton (8-3) set up for the final shot. Oliver missed a 3-point attempt with 2 seconds left and teammate Khari Price rebounded, but his one-handed push shot would not fall at the buzzer.
Price was in for leading scorer Kevin Dillard, who left the game with 4:19 to go due to back spasms.
Tyler Brown added 16 points and Jon Ekey 13 for the Redbirds, who led by 12 points early, but fell behind by four with 9:56 to go before regaining the advantage.
Dillard and Dyshawn Pierre led Dayton with 14 points apiece.