Mack's 3-pointer with 1:21 left in overtime gave Butler the lead for good at 72-70.
Kenny Boynton missed a long 3 that could have given Florida (29-8) the lead with a little under 20 seconds left. Alex Tyus appeared to have the offensive rebound, but Howard tied him up and the possession arrow favored Butler.
Florida had to foul Mack with 10.6 seconds to go, and he hit both shots for the final margin.
