The Badgers shut out Northwestern for the game's first 5:30 and held the Wildcats to just 12 first-half points. Northwestern shot only 29 percent from the field with more than half (8-of-15) of its field goals coming from 3-point range.
Wisconsin improved to 19-8 for the season and to 10-4 in the Big Ten Conference, winning for the fifth time in six games.
Northwestern (13-14, 4-10) was led by Reggie Hearn with 13 points. The Wildcats have lost four in a row.