ST. LOUIS — North Carolina had a startling 63 rebounds and blocked eight Ohio shots, and Ohio made just three of its first 20 from the field.

ST. LOUIS — North Carolina had a startling 63 rebounds and blocked eight Ohio shots, and Ohio made just three of its first 20 from the field.

All numbers that would suggest a Tar Heels stampede in their NCAA tournament Midwest Regional semifinal game Friday at the Edward Jones Dome.

But those weren't the only oddities to the matchup, which also featured UNC committing a season-high 24 turnovers, missing 10 free throws (in 24 attempts) and Ohio making 12 of 32 3-pointers as it hit just 11 of 39 inside the arc.

And so it was that the 13th-seeded Bobcats forced No. 1 seed Carolina into overtime and stood on the verge of becoming the highest-seeded team to topple a No. 1 since the NCAA field expanded to 64 teams in 1985.

Instead, the Tar Heels bristled in the extra session, holding Ohio without a basket in six attempts and outscoring it 10-2 to prevail 73-65.

UNC forward Harrison Barnes shrugged away an otherwise dismal game by scoring five points in overtime to atone for his three-of-16 overall shooting and five turnovers.

"The youngster has an ability to make plays, and he's not afraid to try to make plays," UNC coach Roy Williams said.

Seven-footer Tyler Zeller led Carolina with 20 points and 22 rebounds, keyed, he said, by "my height and weight" advantage. Reggie Bullock added 17 for UNC on five-of-10 3-point shooting.

Afterward, the Tar Heels were more relieved and drained than thrilled.

Williams had been so lathered up between the the end of regulation and overtime that he felt dizzy in the huddle and joked that he thought to himself, "If I'm going to die, let's at least die with a win."

And even the win only went so far.

"We've got to get some joy in Mudville, because our locker room wasn't as happy as you want it to be when you get to the final eight," Williams said, adding, "We realize we escaped."

Said Zeller: "I think we feel like we got away with one."

Walter Offutt led Ohio (29-8) with 26 points, including six 3's in 10 attempts, but after the game his first thought was of the free throw he missed with 25 seconds left in regulation.

"It feels terrible," Offutt said.

Ohio had won multiple NCAA tournament games for the first time since 1964, but that was of little immediate consolation to the Bobcats.

"There's nothing I can say to them at this point that's going to take away the sting," Ohio coach John Groce said.

North Carolina (32-5) advanced to Sunday's regional final against the winner of the late Friday game between second-seeded Kansas and No. 11 seed North Carolina State.

The Tar Heels now are 5-0 in NCAA games in the state of Missouri, including two wins apiece in the 1957 Final Four in Kansas City and the 2005 Final Four in St. Louis.

As expected, Carolina played without point guard Kendall Marshall, who has a broken bone in his right wrist.

That left Carolina turning to reserves Stilman White, a freshman, and senior Justin Watts, who had had 19 assists between them all season compared to Marshall's 21 in UNC's two previous NCAA tourney games.

While it was anticipated Marshall's absence could leave Carolina rudderless, White wasn't a liability.

He had six assists and no turnovers in 32 minutes — seven more minutes than he'd played in UNC's three ACC tourney and two previous NCAA games combined.

"He was really something," Williams said.

For context, that was as many assists as Ohio guard D.J. Cooper had with four fewer turnovers.

And Cooper struggled otherwise, too, making just three of 20 field goals and one of 10 from 3-point range.

Carolina had seemed to seize control of the game early, with three dunks among its first five baskets to go up 14-4 as Ohio converted just two of its first 14 attempts.

While so much had been focused on whether Marshall could play, Carolina's skyscrapers made the point relatively moot early as the Tar Heels outscored Ohio 18-6 in the paint in the first half.

Carolina went up 26-11 on a breakaway layup by P.J. Hairston and White's assist to Zeller.

But Nick Kellogg and Offutt hit back-to-back 3s to cut it to 26-17 to give the Bobcats their first flicker of hope, and Carolina made just one basket in the last 6:58 of the half to lead just 29-22 despite Ohio going eight of 35 from the field.

Offutt opened the second half with a 3 to whittle the lead to just 29-25, but UNC uncorked three baskets in 48 seconds thanks to two Ohio turnovers to make it a 10-point game again.

But two more 3s by Offutt 3 made it a four-point game again.

Then T.J. Hall hit another, and presto, Carolina was clinging to a mere 37-36 advantage.

Moments later, a Kellogg 3 gave the Bobcats their first lead at 47-46 with 8:30 to go, and they went up 57-53 on two free throws by Cooper.

Barnes tied it 57-57, though, by essentially converting a four-point play with a free throw and a 3-pointer after missing the second free throw.

They stayed tethered down the stretch, with Bullock's 3 with 39 seconds to go giving Carolina a 63-61 lead.

With 25 seconds left, Offutt had a chance to put Ohio back ahead with a free throw when White fouled him on his made bucket. But he couldn't convert.

Then Barnes fumbled as he tried to take Carolina's last shot of the half, giving Cooper the opportunity for a half-court loft at the buzzer that hit off the back iron.

Bullock opened the overtime with a 3, and Barnes added a basket to make it a five-point game.

Ohio countered only with two Kellogg free throws.