The Buckeyes (26-7) won their eighth consecutive game and captured their fifth conference tournament title.
The second half was a tightly-contested affair that featured six ties and nine lead changes during the first 13 minutes of the period. But after Wisconsin freshman Sam Dekker hit a short jumper with 7:03 remaining to give his team a 41-39 lead, the Badgers were shut down by a punishing OSU defense.
Wisconsin (23-11) managed only five shots during those final seven minutes while Ohio State finished the game on an 11-2 run.
Junior swingman Deshaun Thomas hit a pair of free throws at the 6:42 mark to tie the game for the final time at 41, and then junior point guard Aaron Craft went coast to coast and scored on a spinning layup to give the Buckeyes a 43-41 lead with 5:29 to play.
Wisconsin senior forward Ryan Evans missed the front end of a one-and-one on Wisconsin's next trip down the floor, and then at the other end, OSU sophomore LaQuinton Ross converted an offensive rebound into a basket while drawing a fourth foul against Ryan.
That made it 45-41 in favor of the Buckeyes with 4:27 to play, and Ross padded the lead to 47-41 at the 2:40 mark when he powered his way into the paint and scored from short range.
Wisconsin got two of those points back after sophomore guard Traevon Jackson bagged a pair of free throws to make it 47-43 with 2:27 to play, but the Badgers seemed to get impatient after that.
Junior guard Ben Brust and senior forward Mike Bruesewitz each fired up quick threes early in their team's next two possessions, and when both missed the mark, Wisconsin had missed its chance to get back in the game. Thomas connected on a pair of foul shots with 44.3 seconds remaining, and hit one of two attempts at the 0:33.3 mark to account for the final score.
Thomas had a game-high 17 points for the Buckeyes despite making only 6 of 19 shots, including none of his six attempts from three-point range. Ohio State shot only 38.5 percent (20 for 52) as a team, and made just 1 of 16 attempts (6.3 percent) from behind the arc.
Craft added nine points and six rebounds, but had no assists as Wisconsin successfully sealed off many of his passing lanes. Sophomore Sam Thompson added eight points and three rebounds while Ross totaled seven points, four rebounds and a steal.
Jackson was the only Wisconsin player in double figures, and he barely made it with 10. The Badgers shot only 38.3 percent (18 for 47) from the floor and made only 3 of their 18 three-point attempts (16.7 percent).
Ohio State drew first blood in the game when Thompson flushed a two-handed dunk off an assist from Craft to give the Buckeyes a 2-0 lead at the 18:52 mark.
That was part of an opening salvo that saw five different OSU players score as the Buckeyes opened a 13-6 advantage with 12:56 remaining in the first half.
But Wisconsin responded with a 14-0 run over the next 5½ minutes, a spurt reminiscent of its 18-0 streak that buried Ohio State during a 71-49 loss to the Badgers in Madison on Feb. 17.
Unlike in that game, however, the Buckeyes fought back. After Wisconsin upped its lead to 24-15 with 3:22 to play, OSU closed the half with its own 8-0 flurry. Six of those points came on three baskets in a row from Thomas, who had missed six of his first seven shots from the floor.
The closing first-half rush allowed Ohio State to draw within one of the Badgers at 24-23 sat the break despite making only 10 of its 27 shots from the field (37.0 percent), including misses on all five attempts from behind the arc.
OSU's shooting didn't get much better in the second half, but it managed to grab the upper hand early when sophomore center Amir Williams scored his first basket of the tournament to give the Buckeyes a 25-24 lead just 27 seconds into the period. Williams finished the game with five points and four rebounds.
That set up a back-and-forth battle that saw the lead change hands nine times as well as six ties before Dekker made Wisconsin's final field goal at the 7:03 mark.
Ohio State won the Big Ten tournament championship for the fourth time under head coach Thad Matta and the fifth time overall. Matta guided the Buckeyes to previous titles in 2007, 2010 and 2011, and OSU also won the championship in 2002 under head coach Jim O'Brien.