Michigan, which went cold late in the first half, has opened a seven-point lead on Wisconsin early in the second.
The Wolverines have scored the first six of the half, and lead 39-32 at the first media timeout.
Derrick Walton Jr. has 14 points for Michigan, while Zak Irvin has nine and D.J. Walton and Mo Wagner have seven each.
Wolverines up 1 at halftime
Michigan was once up 10 points in the first half.
Its halftime lead is now one, 33-32.
The Wolverines, which were shooting 62.5 percent midway through the half scored once (a 3-pointer from Zak Irvin with 1:29 left) in the final five minutes.