Campbell made a career-best four 3-pointers as part of 8-for-15 shooting, and the 6-foot-8 junior was a perfect 7-for-7 at the foul line. He sank two free throws to lift Ohio ahead 43-42, capping a 10-3 surge to open the second half. Fifteen of his 27 points came after halftime.
Francis Kiapway led Ball State with 21 points, scoring 18 in the second half as the Cardinals tried to hang on. Kiapway nailed five 3's in a row in the second half, finishing 6-for-8.
Ball State made up most of a 10-point gap in last 3:38 but Khari Harley stole from Kiapway and drove for a score.
Simmons scored seven straight points for Ohio in roughly 90 seconds late in the game.