Johnny Hill had a career-high 24 points (all in the second half), Bryant Allen added 22 and Jackie Carmichael had 19 points and 12 rebounds for Illinois State (9-8, 0-5), which has lost five straight.
Drake trailed for most of the first half, falling behind 41-32 at halftime, but opened the second half with a 25-6 run to take a 57-47 lead with 12:43 remaining.
The Redbirds got as close as 77-73 on Hill's three-point play with 37 seconds left, but Drake hit 5 of 6 free throws the rest of the way to close it out.
Purdue coach Matt Painter says players haven't used the fifth-year graduate transfer rule for its true intent.
The dust has settled after players made their NBA draft decisions. Which college teams won? Which lost? Well, Villanova is pretty happy. USC, meanwhile, might not be as thrilled.
The 2017 recruiting class is short on point guards, with Trevon Duval leading only eight prospects from the ESPN 60 who are still available.