The quarterfinal victory advanced Wisconsin (22-10) into the tournament semifinals Saturday against No. 3 Indiana (27-5), which defeated Illinois 80-64 Friday. Michigan (26-7) will sit back to see where it is seeded for the NCAA Tournament.
No. 9 Ohio State also moved on with a 71-50 blasting of Nebraska and will take on No. 7 Michigan State in the semifinals after the Spartans fought off Iowa 59-56.
The Wisconsin win was an upset in the rankings but not on the Big Ten bracket, which seeded Wisconsin fourth and Michigan fifth.
The Badgers were a woeful 5-of-29 (17.2 percent) shooting in the first half but trailed just 20-17 at the half after Jackson hit a late three-pointer.
Wisconsin shooters heated up in the second half, hitting 17-of-28 (60.7 percent) -- and the Badgers quickly moved into the lead, pushing the advantage to eight and putting the game away with a series of free throws, including four by Jackson in the final 41 seconds.
Ben Brust backed Jackson with 14 points and Ryan Evans added 12 for Wisconsin.
Michigan's Trey Burke had 22 points on 8-of-22 shooting for game honors.
In the earlier game, Cody Zeller scored 14 of his 24 points in the first half in pacing Indiana to the win.
Indiana jumped out to a 10-2 lead and really wasn't threatened from there.
Zeller scored eight points in a 10-2 Indiana run that pushed the early lead to 22-7. The Hoosiers were up 35-21 at halftime after Zeller dropped in a short shot. Indiana had a double-figure lead through almost the entire second half.
Zeller was 9-of-11 shooting and made all six of his free-throw attempts in scoring 24 points. He also had eight rebounds. Christian Watford added 15 points and Victor Oladipo scored 12 points and had 11 rebounds.
Illinois (22-12) got 16 points each from Brandon Paul and Tracy Abrams.
Deshaun Thomas and Sam Thompson both scored 19 points for Ohio State (24-7), which hit a sizzling 59 percent from the field against Nebraska. The Buckeyes broke things open in the second half after leading by only five at the break.
The Cornhuskers could not maintain their early momentum after they took a 15-6 lead. Nebraska came up with just seven points from its bench players.
Gary Harris gave Michigan State a three-point lead at the Hawkeyes with 30 seconds left and the Spartans survived a pair of missed 3-point attempts down the stretch.
Iowa had an eight-point lead at the midway point of the second half, but went almost 5 minutes without scoring while Michigan State was going on an 8-0 run to get back in the contest.
Adreian Payne led the Spartans (25-7) with 18 points.