A dunk by Tyler Griffey with 8:46 remaining put Illinois up 64-46. The margin was too much for a Boilermakers team that had already tried to dig out of a 16-point first-half hole.
Griffey scored 12 points and Joseph Bertrand had a career-high 12 rebounds.
Terone Johnson led Purdue (12-13, 5-7) with 18 points. Boilermakers coach Matt Painter was ejected for arguing with officials with just over eight minutes to play.