The Illini survived a late Purdue charge but a Nnanna Egwu dunk with 18 seconds left put the Illini up 64-57.
Malcolm Hill led Illinois (13-7, 3-4 Big Ten) with 18 points. Leron Black had 15, Kendrick Nunn 14 and Egwu 11.
The Illini shot just 28.6 percent in the first half but somehow went to the locker room with a 32-30 lead.
Illinois also relied on efficient free throw shooting while keeping the Boilermakers away from the line. Illinois was 21 of 24 while Purdue was just 4 of 9.
Jon Octeus and Raphael Davis led the Boilermakers (11-8, 3-3) with 14 points each.
Purdue played most of the game without leading scorer Kendall Stephens who left with an unspecified injury.
