Ross had back-to-back baskets midway through the second period that put the Buckeyes (14-0, 1-0 Big Ten) up 52-46. Purdue twice got within four points but Aaron Craft assisted on 3-pointers by Marc Loving and Shannon Scott that pushed Ohio State further ahead.
Ross scored seven straight points for the Buckeyes, with a tip-in with 4:53 to go making the score 67-57.
Ohio State made 9-of-10 free throws the rest of the way to put the game away.
Scott had 18 points and Lenzelle Smith Jr. 14 to back Ross in the Buckeyes' scoring column.
A.J. Hammons paced Purdue (10-4, 0-1) with 18 points and 16 rebounds. Ronnie Johnson added 16 points and Terone Johnson 13 for the Boilermakers.