Dayton, an 11-seed, will face Syracuse on Saturday in the next round of the NCAA Tournament.
Vee Sanford's runner in the closing seconds gave Dayton the lead and Aaron Craft's driving layup at the buzzer rolled off the rim, as the Flyers pulled off a 60-59 victory over No. 6 Ohio State in the opening game of the second round.
Dayton took a 55-52 lead with 2:35 remaining on a pair of free throws by Jordan Sibert, but a three-point play by Craft on the ensuing trip tied it for the Buckeyes.
Devin Oliver then missed a pair from the free-throw line for Dayton and Ohio State countered at the other end with a floater in the lane by Sam Thompson with 57 seconds left.
The Flyers worked the ball around the perimeter on the next possession and Dyshawn Pierre was fouled on an attempt from beyond the arc with 26.3 seconds to play. He calmly sank all three from the line to give Dayton a 58-57 lead.
Craft, though, made an acrobatic layup through traffic with 17 seconds left to again put the Buckeyes in front.
Sanford took the inbounds after a timeout and raced down the right side of the lane, banking a shot home to give the Flyers the lead. Craft took off the other way and got to the lane before putting up a shot that hit the backboard and slipped off the rim as time expired.