CHICAGO -- DeShaun Thomas was Ohio State's indispensable man Saturday.
The Buckeyes might not be bound for the Big Ten championship game without his late heroics in a 61-58 semifinal victory over Michigan State at the United Center.
The Ohio State forward collected a key offensive rebound with 55 seconds to play, scored on jumper 33 seconds later and added a free throw with eight seconds left as the Buckeyes stymied a late Spartans comeback.
Thomas scored 16 points and teammate Aaron Craft had 20 and nine assists as the No. 2 seed Buckeyes (25-7) landed a spot against Wisconsin in Sunday's tournament title game.
"The shot I hit, that was a great play (call) by coach and great screen by Evan Ravenel," Thomas said. "He said, 'You're going to knock one down, just be patient.' Finally I did, and it went in."
While Thomas had the late heroics, Craft was a dependable and critical contributor throughout.
"He makes us go on both ends of the floor," said Ohio State coach Thad Matta, whose team won its seventh straight. "He loves these type of games. There's no question about it. He's big for us."
Derrick Nix topped Michigan State (25-8) with 17 points and nine rebounds. Keith Appling scored 16 points and Adreian Payne added 12.
Ohio State jumped in front early in the second half on a Lenzelle Smith Jr. layup but struggled to create breathing room until the the 7:23 mark after Craft hit back-to-back jumpers for a 55-49 lead.
But the Buckeyes couldn't seal the deal. Appling hit a 3-pointer with 3:24 left and Nix added a 3-point play with 1:54 remaining to nearly erase the Ohio State lead.
Trailing 57-56 with 1:27 left in regulation, Michigan State was hit with a flagrant foul, Craft made a free throw to push the lead to 58-56 and the Buckeyes retained possession.
Shannon Scott's subsequent baseline 3-point try failed, but Thomas secured the offensive rebound. He scored on short jumper, added a defensive rebound and hit a free throw for a 61-56 lead.
A jumper by Michigan State's Denzel Valentine with one second left narrowed the final margin.
"They played smarter than us down the stretch," Spartans coach Tom Izzo said. "We weren't the toughest team. We played hard, nothing wrong with that, but we weren't as tough as we usually are. (And) today we weren't the smarest team and they were and they got what they deserved."
The Spartans led 29-28 at halftime after six lead changes and three ties.
Nix led Michigan State with 10 points and Payne, Friday's scoring leader, had a slow start but gave the Spartans the halftime edge with a dunk with 1:15 remaining.
Thomas scored a team-high 11 first-half points, despite hitting just 4 of 13 shots from the field. The Buckeyes made just 11 of 32 from the field (34.4 percent).
Michigan State's largest lead came early when Payne hit a 3-pointer for a 13-7 lead with 14:03 left in the first half. Ohio State later went up 28-23 after a Thomas jumper with 4:26 left.
The Spartans then closed the half with six straight points.
Michigan State shot 48.1 percent from the field and outrebounded Ohio State 37-32. But the Spartans had 12 turnovers to five for the Buckeyes.
"The great thing for us is that we didn't turn over and give them opportunities," Matta said. "Our ability to take care of the basketball was probably the difference."
Michigan State has lost in the Big Ten tournament before yet rebounded to reach the NCAA Final Four.
Izzo said this game will serve as motivation as the Spartans look to the NCAA tournament.
"I'm going to use this a lot," he said. "Hopefully, it will pay dividends."
NOTES: The Buckeyes are 21-9 all time in the tournament and coach Thad Motta is 18-5 overall with three championships (2007, 2010 and 2011). ... Chicago was a great location for Michigan State in the tournament's early years. The Spartans won titles in 1999 and 2000 but were 1-1 the last time the tournament was in the Windy City (2007). ... Michigan State is 19-13 in the Big ten tournament, including 3-7 in the semifinals. ... Spartans guard Gary Harris' 13.2 scoring average ranked third among freshman in program history. ... Ohio State's Friday victory over Nebraska was its ninth in 11 meetings and the Buckeyes are 6-0 as a ranked team. ... With 19 points against the Cornhuskers on Friday, Thomas moved to No. 17 on Ohio State's career scoring list with 1,524 points. ... Michigan State still leads the overall series with Ohio State 61-55 but is 2-3 on neutral courts ... Sunday's title game will be televised nationally on CBS at 3:30 p.m. ET.