The Fighting Illini (6-1, 2-1) had averaged 34 points a game this season before being held to a lone touchdown. That score did not come until Nathan Scheelhaase hit Evan Wilson with a 3-yard pass less than 7 minutes from the end of the game.
Drew Basil supplied the only first-half points with a 43-yard field goal in the opening quarter and the Buckeyes (4-3, 1-2) broke things open thanks to a key defensive play early in the second half.
Bradley Roby intercepted a pass by Scheelhaase on the second play of the third period and returned it 37 yards to the Illinois 12. Herron scored a rushing touchdown on the next play.
Ohio State took a 17-0 lead early in the fourth quarter on freshman Braxton Miller's 17-yard pass to Jake Stonebruner.
The Buckeyes forced three turnovers and Illinois had to punt the ball away six times.