A.J. Graves scored 15 points and Matt Howard added 12 for Butler (12-2 Horizon League), which is a school-best 23-2 for the second consecutive season.
Byron Davis led Youngstown State with 20 points and Vance Cooksey added 15 for the Penguins (8-17, 4-11), who have lost eight of nine.
Butler set season highs for points and field goal percentage (.623).
INDIANA: Getting rid of coach Kelvin Sampson might not be the solution to Indiana's problems. It's a move that might just create a bigger mess.
When Sampson was accused Wednesday of five major NCAA infractions, it immediately set off a widespread debate over what the university should do next and whether Sampson should continue coaching at Indiana, which hasn't had a major NCAA rules violation in nearly half a century.
Sampson's deal includes termination clauses for violations of university or NCAA rules that eliminate the payments. Attorneys, however, have differing views on whether the accusations, which include providing false or misleading information to investigators, would allow Indiana to fire Sampson with cause and get off the financial hook.
The university has until May 8 to respond to the NCAA's report. Sampson and university officials are scheduled to appear before the infractions committee June 14, with a final ruling expected within a month.
University spokesman Larry MacIntyre confirmed Thursday that president Michael McRobbie was still consulting with the school's lawyers, trustees and administrators. MacIntyre would not provide details on those discussions but acknowledged both sides have to abide by the rules set forth in the contract.