The Buckeyes (25-5) broke open a close game early in the second half, scoring the first 11 points of the half as part of a 20-7 run to take a seemingly comfortable 45-29 lead with 10:51 remaining in the game.
But the seventh-seeded Wolverines (20-11) made each of their next four shots – including three-pointers from senior guard Carmen Reynolds and freshman guard Brenae Harris – for a 10-0 run to close the gap to six points at 45-39 at the 7:39 mark.
Michigan managed to stay within striking distance until a three-pointer from senior guard Courtney Boylan cut the margin to five at 53-48 with 1:03 remaining.
That was as close as the Wolverines would get, however.
OSU senior point guard Samantha Prahalis converted a one-and-one with 54.4 seconds remaining to push her team's lead back to seven at 55-48 before junior guard Tayler Hill stole the ball from U-M junior center Rachel Sheffer at the other end.
Hill followed that by bagging both ends of another one-and-one to push the Buckeyes' lead back to nine with 23.9 seconds to play, and then junior guard Amber Stokes drew a charge on Boylan with 17.0 seconds remaining to put the final nail in Michigan's coffin.
The fact that Ohio State tied its season-low point total and the Buckeyes utilized crucial defensive stops in the waning seconds – by Hill and Stokes, both members of the Big Ten all-defensive team – was not lost on head coach Jim Foster.
"I thought our defense was excellent today," Foster said. "You have to have a mentality to be a good defensive player and I thought we did a pretty good job of staying with individual responsibilities."
Hill came alive in the second half for the Buckeyes. After tallying only three points on 1-for-4 shooting during the first half, she hit 6 of her 8 shots in the second half to finish with a game-high 19 points.
Freshman forward Kalpana Beach totaled 12 points and seven rebounds for the Buckeyes while Prahalis added 11 points, eight rebounds and five assists. The assists pushed Prahalis' career total to 894, making her the Big Ten's all-time leader. Nancy Kennelly of Northwestern (892, 1990-93) previously held the record.
Stokes filled the stat sheet with four points, a game-high nine rebounds – which tied a career-best total – two assists, one steal and a blocked shot.
Reynolds, a product of Hilliard (Ohio) Davidson, led the Wolverines in scoring with 14 points. Boylan scored 10 and tied Prahalis for game-high honors with five assists.
Neither team shot the ball well. OSU made only 23 of 60 attempts from floor for 38.3 percent while Michigan was 19 for 55 (34.5 percent). The teams were even worse from three-point range. The Buckeyes made only 5 of 16 treys (31.3 percent) while the Wolverines missed 12 of their first 13 attempts from three-point range and finished 7 for 25 (28.0 percent).
Compounding the shooting problems for both teams was the fact they turned the ball over at an alarming rate. Ohio State committed 21 turnovers while Michigan threw the ball away 17 times. The Buckeyes entered the game averaging only 14.0 miscues per game while the Wolverines were averaging 13.0.
Ohio State advanced to the tournament semifinals to play the winner of the quarterfinal match between No. 3 seed Iowa and sixth seed Nebraska. Tip time is 5 p.m. Eastern.