Buffalo 76, Ball St. 61
Javon McCrea added 16 points and 11 rebounds for the Bulls (14-19), whose 74-72 overtime win against Central Michigan in the opening round snapped a two-game skid.
Ball State (15-15) built a 36-26 lead with 1:39 left to play in the opening frame. However, McCrea converted a layup on Buffalo's next possession, sparking a 29-8 run for the Bulls. Regan capped the run, which spanned nearly 8 minutes, with a 3-pointer.
McCrea and Regan hit back-to-back shots with just under 3 minutes left to give the Bulls their biggest lead, 74-54.
Buffalo made 16 of 25 shots and outscored Ball State 46-25 in the second half.
Jauwan Scaife scored 28 for fifth-seeded Ball State, which went 20-of-56 shooting. Majok Majok added 10 points.