After falling behind by one early, the Buckeyes (20-6, 10-3 Big Ten) used an 18-6 run to finish the Illini (17-9, 9-4) off early.
By the end of the run Ohio State led 21-10 with 11:48 to play. The Buckeyes were up 36-20 at the half and never led by less than 13 over the final 20 minutes.
Demetri McCamey led Illinois with nine points — nearly seven short of his average.
The win kept the Buckeyes in a first-place tie in the Big Ten with Michigan State. The Illini fell from the top spot and are a game back of the leaders.