Senior quarterback Tyler Donovan threw for one touchdown and scrambled for another as Wisconsin held off a fourth-quarter rally to upset No. 12 Michigan 37-21 on Saturday.
The Badgers (8-3, 4-3 Big Ten) snapped the Wolverines' eight-game winning streak, robbing Michigan of momentum going into its annual matchup with Ohio State.
Michigan (8-3, 6-1) played without injured running back Mike Hart, and Ryan Mallett relieved ailing quarterback Chad Henne in the first quarter.
With Michigan trailing 23-7 and stuck in its own end zone at the beginning of the fourth quarter, Mallett completed a 97-yard touchdown pass to wide receiver Mario Manningham that cut Wisconsin's lead to 23-14.
Mallett threw an interception on Michigan's next possession, but came back to throw a 26-yard touchdown pass to Adrian Arrington to cut the lead to 23-21 with 7:31 left in the game. Mallett kept the drive going with a desperation play, avoiding a sack by tossing the ball backward to Carson Butler, who ran 16 yards for a first down.
A Wisconsin drive stalled after Donovan left the game with an apparent wrist injury, but cornerback Jack Ikegwuonu came up with Wisconsin's third interception to set up a 6-yard touchdown run by Zach Brown that put Wisconsin ahead 30-21 with 3:11 remaining.
Brown scored again less than a minute later, after Mallett threw incomplete on fourth-and-19 from his own end zone to give the ball back to the Badgers near the goal line.