Jared Thornton added 17 points and Tim McCulley had 16 for Notre Dame.
Tom Kanaley topped DeSales with 23 points.
The Saints trailed by six after three quarters, but tied the game at 59 midway through the 4th quarter when Isaiah Merced stole the ball at midcourt and broke away for an easy layup.
Batavia ND took the lead on a free throw, then Hotze scored back to back baskets and picked up a foul on the second hoop, giving the Irish a six point lead.
Raymond Sims scored to draw Geneva within four, but Thornton answered again as Geneva regained a six point lead with less than a minute to go at 67-61.
Kanaley hit a three to keep the game interesting with 23 seconds left, but the Irish made two free throws to seal the win.
Batavia ND advances to Saturday's state quarterfinals. The Irish will play at Noon at Buffalo State College.