Nate Reuvers had 17 points, including the go-ahead basket with under two minutes to play, leading Wisconsin to an upset over No. 5 Ohio State, 61-57, in Columbus on Friday.
Kobe King had 13 points and Brevin Pritzl nine for the Badgers (9-5, 2-1 Big Ten).
Kaleb Wesson had 22 points and tied his career-high with 13 rebounds for the Buckeyes (11-3, 1-2), who have lost two straight and three of five.
Wisconsin battled back from a seven-point deficit to take a 52-51 lead with 1:54 left when Reuvers made his first field goal of the second half.
Pritzl hit a 3-pointer for the Badgers to make it 55-51, but Duane Washington Jr. (18 points) countered with a trey for the Buckeyes as the Badgers led 55-54 with 57 seconds left.
D’Mitrik Trice hit two free throws for Wisconsin before Wesson missed a 3 at the other end.
Reuvers added a pair from the line with 14 seconds left for 59-54 advantage to ice the victory.
The Buckeyes trailed 29-25 at the half but scored 10 straight points as part of a 13-2 run that gave them a 38-31 lead with 14:18 left while the Badgers missed seven shots in a row.
This was the first game for Wisconsin forward Micah Potter against his former team. The Mentor, Ohio, native transferred from Ohio State before the start of the 2018-19 season. He had four points.
The Badgers trailed 9-2 to open the game but went ahead on 3-pointer by Trevor Anderson on the fast break with 42 seconds left in the first half to make it 26-25. Aleem Ford hit another trey with four seconds left to extend the margin to four to cap an 8-0 run in the final 1:14.
The Buckeyes played without junior starting forward Kyle Young (8.3 ppg., 6.8 rpg) because he had his appendix removed on Sunday.
Ohio State plays at No. 15 Maryland on Tuesday. Wisconsin hosts Illinois on Wednesday.
—Field Level Media