Ohio State narrowly escaped with a victory in the Big Ten tournament quarterfinals.
It had a couple of close calls in the regular season against Michigan, as well.
The top-ranked Buckeyes look to advance to the tournament championship game for the fifth time in six years Saturday in Indianapolis when they face a Wolverines team that needed a furious comeback to make the semifinals for the first time in seven seasons.
Ohio State (30-2) beat Northwestern on Friday to solidify itself as a No. 1 seed for the NCAA tournament, while fourth-seeded Michigan (20-12) defeated Illinois to bolster its chances of making the field of 68.
Neither win was easy.
The defending tournament champion Buckeyes needed overtime to defeat the eighth-seeded Wildcats 67-61, and the Wolverines rallied from 12 down and scored 21 of the game's final 25 points in a 60-55 win over the Illini.
Ohio State, which has advanced to the tournament championship game in four of the last five years, was bailed out by Jared Sullinger and some stingy defense.
Sullinger struggled mightily from the field, missing 10 of 12 shots, but finished 16 of 18 from the foul line. The Big Ten freshman of the year had 20 points and 18 rebounds - one shy of the tournament record - and made all 10 of his free throws in overtime.
The Buckeyes attempted just two field goals in the extra session, scoring 12 of their 15 points from the charity stripe.
Their free-throw shooting also proved to be key in their first meeting of the season with the Wolverines.
In a 68-64 win at Michigan on Jan. 12, Ohio State was held without a field goal for the last 8:36 - its last 11 points came on free throws. The Wolverines did a good job of frustrating Sullinger, limiting him to 12 points and seven boards while forcing a season-worst six turnovers from the freshman.
Sullinger played much better in Columbus three weeks later, finishing with 19 points and 15 rebounds, but the Buckeyes trailed by six points early in the second half before pulling away for a 62-53 victory.
Ohio State has won four straight in the series, which includes a 69-68 victory in last season's tournament quarterfinals on Evan Turner's 37-foot shot at the buzzer.
The Buckeyes advanced Friday despite shooting 32.2 percent to match their season low.
"Obviously we never got into our flow offensively, and when shots weren't falling, I was fine with that," coach Thad Matta said. "But hopefully we can shoot the ball a little better (Saturday)."
Matta could tolerate the offensive struggles because his defense played so well. Ohio State, 11th in the nation in scoring defense at 59.8 points, held the Wildcats to 37.3 percent shooting and outrebounded them 48-27.
"We've just got to keep playing defense like we did (Friday)," Sullinger said. "Our defense carried us. We didn't really hit shots, so we obviously can win without hitting shots and just keep playing 'D.'"
Michigan's defense also stepped up late Friday.
Trailing 51-39 with just over eight minutes remaining, the Wolverines forced five turnovers and held the Illini to 1-of-8 shooting the rest of the way.
"We just came out and just stayed hungry and just maintained our focus and poise on the defensive end and the offensive end," freshman guard Tim Hardaway Jr. said.
Hardaway finished with 16 points, while Darius Morris scored 17 for the Wolverines, winners of nine of 12.
"We've got some confidence going into (Saturday's) game," Michigan guard Zack Novak said. "(The Buckeyes are) having a great year, got a really good team, but we feel like we're playing pretty good right now."
The Wolverines are in the semifinals for the first time since 2004. They haven't advanced to the title game since winning the inaugural Big Ten tournament in 1998.