CHICAGO (Ticker) -- Sean Connolly scored 21 points and Brent Darby buried all eight of his free-throw attempts - including four in the final 40 seconds - as Ohio State stunned No. 18 Wisconsin, 58-50, in a quarterfinal matchup of the Big Ten Conference Tournament.
Connolly was 5-of-7 from 3-point range and Darby finished with 16 points as Ohio State knocked off the regular-season conference champions. After just getting by Iowa in its opening-round game, the Buckeyes made all the plays down the stretch.
After Velimir Radinovic converted a loose ball scramble into his only basket of the second half and a 53-48 lead with 56 seconds to go, Darby sealed the win by making his free throws down the stretch.
Ohio State (16-13) advances to face Michigan State in a semifinal matchup Saturday.
"We've just got to go one game at a time and if we win that game, then we can look forward to the championship game," Connolly said.
"It was a terrific win," Ohio State coach Jim O'Brien said. "I couldn't be more proud of our guys. We were very good defensively today. It was a character and heart kind of win. It was a gritty, gritty effort from our players and we are thrilled to be moving on."
Wisconsin's loss marks the fourth time in six years that the Big Ten Conference Tournament top seed has been bounced in its opening-round game.
Kirk Penny led the Badgers with 14 points but Wisconsin (22-7) shot just 34 percent from the field. Despite the loss, the Badgers are a lock to be one of the at-large teams selected when the NCAA Tournament field is announced on Sunday
"We are not thinking about anything yet," Penny said. "We are disappointed in the way we played. We just have to improve from here."
"We don't worry about our seed," Wisconsin guard Delvin Harris said. "We wanted to win no matter what. We play the next game no matter who we are playing or what we are playing for. We want to win just as much as anybody. It doesn't matter what we are playing for or what we are seeded."
Wisconsin coach Bo Ryan was not sure having the extra time off before the tournament was a benefit to his team.
"An optimist would say that `yes' it is an advantage to have the time," Ryan said."But once again, I can't say that because I am not an optimist either. We just have to be thankful that we played well in the regular season and will get a chance to play (in the NCAA Tournament)."
Ohio State led 30-25 at the half but Wisconsin opened the second half with an 11-1 run to seize the lead. But Zach Williams buried a jumper and Darby hit two free throws to draw the Buckeyes within 36-35. Williams then broke free for a layup with 14:29 to go, putting Ohio State ahead for good.
Wisonsin got within 42-41 on a 3-pointer by Penny with 8:16 remaining but Darby had a layup and jumper 79 seconds apart to push the led to five. The Badgers were within 51-48 following a 3-pointer by Freddie Owens with 95 seconds.
Following a timeout, Wisconsin played strong defense and forced Williams into a missed jumper. The rebound resulted in a scramble near the basket, Radinovic came up with the loose ball and calmly scored a back-breaking basket.
Harris had two free throws for Wisconsin with 55 seconds left and Connolly missed the front end of a 1-and-1. But Harris committed a turnover for the Badgers and Darby sank two free throws for a 55-50 edge.
After Clayton Hanson missed a 3-pointer with 26 seconds to go, Darby added two more from the line - sealing the upset.
"Our mindset right now is to just take every game one by one," Darby said. "The main thing is just about surviving. We can't afford to look past anyone."
Wisconsin shot just 34 percent (18-of-53) in the contest and was 8-of-28 from 3-point range.
"When shots are not going in, it tends to look more like (we are flat)," Ryan said. "Some guys struggled to hit shots. It happens. ... Hopefully, we can shoot the ball better next game."