Thomas connected on 10-of-12 foul shots and hauled down seven rebounds to provide a spark for the Buckeyes (18-6, 8-4 Big Ten), who snapped a two-game losing streak.
Amir Williams came off the bench to help out with 10 points and eight rebounds in the win.
The Wildcats (13-12, 4-8) were led by Tre Demps with 16 points.
Kale Abrahamson added 13 and Reggie Hearn donated 12 for Northwestern.
Reindeer recovered after escaping from Santa during lighting ceremony
Ukrainian protestors topple Lenin statue [VIDEO]