CHICAGO - Brent Darby heard the whistle and thought he was going to the foul line once more, a chance to win the game for Ohio State with 6 seconds left.

Then he heard the referee call Charles Bass' name. Instead of Ohio State's leading scorer, the game was in the hands of a freshman who'd never even attempted a free throw, let alone made one.

''I went to say something to the referee and Charles told me, 'Don't worry about it, I got it,''' Darby said. ''The way he said it, he had a lot of confidence in his voice. So I stepped away from him and said, 'Do your thing.'''

Bass did. The reserve freshman, only in the game because Velimir Radinovic had fouled out, banked the first shot off the glass to give Ohio State a 55-54 victory over Michigan State in the semifinals of the Big Ten tournament Saturday afternoon.

The Spartans had one last shot, but Chris Hill's 13-footer clanged off the rim as time expired.

''Don't anybody question why Chris' last two shots didn't go in because they're not supposed to,'' Michigan State coach Tom Izzo said. ''We did not deserve to win that game. They deserved to win the game. They outplayed us the entire game.''

Barely above .500 two weeks ago, Ohio State (17-13) will play for the tournament championship - and the Big Ten's automatic NCAA bid - for a second straight year.

The eighth-seeded Buckeyes will play No. 2 seed Illinois which held off Indiana 73-72..

''I knew it was my time to step up. Everyone else had been doing it,'' Bass said. ''Now we got to win a championship tomorrow. I want to win a championship.''

Bass and Darby salvaged what would have been a huge collapse by the Buckeyes. They led by as much as 19 in the first half as they held Michigan State (19-12) to a woeful 15 percent shooting.

But Ohio State made just two field goals in the last 17:09, the last one coming with eight minutes to play. The Buckeyes also played the last 5:58 short-handed after big men Radinovic and Shun Jenkins fouled out.

''It was tough because we knew they were going to keep coming at us,'' Sean Connolly said. ''It's just a testament to us. We kept fighting.''

After trailing the entire game, Michigan State took a 51-50 lead on a 3-pointer by Maurice Ager with 3:43 to play. Knowing the Buckeyes didn't have any inside game, the Spartans clamped down on Darby.

But the 6-foot-1 guard didn't back down, making four foul shots in a 40-second span to give Ohio State a 54-51 lead with 1:59 left.

''We can't play without him. No chance,'' Ohio State Jim O'Brien said of Darby, who was 10-of-10 from the line in the last 9:36.

Hill came right back with a monster 3 to tie the game at 54 and, after trading misses, Ohio State again gave the ball to Darby. But Izzo wasn't going to let him go to the line again.

''I decided if I was going to lose the game, I was going to lose it with the ball in our hands at the end, not theirs,'' Izzo said. ''So I just said, since we haven't been able to stop him once without fouling him, we're going to foul who we thought was their worst free throw shooter.''

That would be Bass.

''I took it personally that they fouled me,'' Bass said.

And he made the Spartans pay, banking the first shot off the glass. As the Ohio State fans roared, the Chicago-area native turned around and pumped his left fist.

''I guess he's been working on that one on his own,'' Darby said. ''I don't know where it came from, but it went down for us.''

Bass missed the second shot and the Spartans got the rebound, but Hill couldn't pull off the last-ditch jumper.

Darby finished with 23 points, including 11-of-13 from the free throw line, and also had five rebounds, three assists and four steals.

Ager led Michigan State with 15, and Hill added 12.

The game might have had a different outcome if Michigan State hadn't been so awful in the first half. The Spartans made only two of their first 19 shots.

''I told them at halftime that they've embarrassed themselves and the university and I really believed that,'' Izzo said. ''That's not to the caliber that we need to play or should play.

''If we would have won that game, as I told my team, they won't be as good of people or players later on. That was not worthy of us winning.''