Sophomore guard Kam Williams came off the bench to deliver a game-high 21 points as Ohio State downed Northwestern 65-56 on Wednesday night in Evanston, Ill., to stay unbeaten in Big Ten play.

Williams drilled 5 of 9 3-point attempts -- accounting for all of the Buckeyes' conversions from beyond the arc -- as Ohio State (11-5, 3-0) won its seventh in a row and joined Indiana, Iowa and Maryland atop the Big Ten standings.

Northwestern (13-3, 1-2), which played without 7-foot senior center Alex Olah for the fourth straight game, was paced by sophomore point guard Bryant McIntosh's 15 points and six assists. However, the Big Ten's assist co-leader (with Michigan State's Denzel Valentine) had four turnovers and the Wildcats shot just 31 percent from the field.

Ohio State built a nine-point lead late in the first half, but backup power forward Gavin Skelly's two hustle baskets inspired Northwestern's 10-0 run to end the half that provided a 27-26 edge.

The teams traded the lead three times early in the second half, but Williams' hot shooting kept the Buckeyes in front whenever McIntosh drew Northwestern close.

After McIntosh drilled a 3-pointer with 3:55 left to pull the Wildcats within 57-53, Ohio State clinched its 28th win in the last 29 meetings in the series with an 8-0 run instigated by a Williams pull-up jumper.

In Olah's absence, senior Joey Van Zegeren started in the post against Ohio State sophomore Trevor Thompson -- a duo that played together at Virginia Tech in 2013-14. In the opening three minutes, Thompson dunked at one end and van Zegeren answered by dunking over Thompson at the other end.

Thompson won the battle of former Hokies with 12 points and 10 rebounds in 22 minutes. Van Zegeren had seven points and three rebounds in 14 minutes.