GREENSBORO, N.C. (AP) — North Carolina opened the Atlantic Coast Conference tournament by reclaiming the form that carried the Tar Heels through February. The only question is whether they’ll have to continue their title chase without the guy who sparked their late-season surge.

P.J. Hairston scored 21 points before leaving the game with a cut to his left hand in the Tar Heels’ 83-62 win against Florida State in Friday night’s quarterfinals.

Hairston, playing in his hometown, suffered a cut to the webbing between his middle and ring fingers — apparently when the ball got jammed in between those fingers. Hairston left a trail of blood droplets as he checked out of the game and then left the bench area in obvious pain with 4:13 left.

The 6-foot-5 sophomore needed eight stitches for the cut to his non-shooting hand. Coach Roy Williams said afterward he didn’t know whether Hairston would be able to play for the third-seeded Tar Heels (23-9) in Saturday’s semifinals against Maryland, which upset second-ranked Duke earlier Friday.

“We’re extremely concerned right now because his hand is torn up,” Williams said. “It doesn’t look good and they’re stitching it up and I wouldn’t watch it.”

Hairston, who didn’t speak with reporters afterward, hit his first four 3-pointers and finished 7-for-11 from the field, including 5-for-6 from behind the arc.

For UNC fans, Hairston’s injury is sure to stir an unwanted feeling of deja vu. It was in last year’s quarterfinal win that forward John Henson suffered a wrist injury that sidelined him for the rest of the ACC tournament.

And it was nearly a year to the day since point guard Kendall Marshall — the Tar Heels’ most irreplaceable player — suffered a broken right wrist when he took a hard foul in an NCAA tournament game here in the Greensboro Coliseum. The injury sidelined Marshall the rest of the way and ultimately derailed UNC’s national-title chances.

If Hairston is out, it will certainly make things tougher as the Tar Heels try to win the tournament for the first time since 2008. After all, the Tar Heels didn’t climb the league standings until Williams inserted Hairston into a four-guard starting lineup.

“He’s a pretty tough kid, so hopefully he’ll be able to shoot around tomorrow, and he’ll be back ready to play,” senior Dexter Strickland said.

Reggie Bullock added 13 of his 17 points after halftime for North Carolina, which took control with a 13-0 run early in the second half. UNC hit 10 3s and also scored 27 points off 18 turnovers to beat the reigning champion Seminoles in a rematch of last season’s championship game.

Michael Snaer scored 20 for sixth-seeded Florida State (18-15), which lost all three meetings with the Tar Heels this season with the last two coming by 21 points each.

The Seminoles advanced to the quarterfinals by holding off 11th-seeded Clemson in the first round Thursday night. But they struggled to slow Hairston early and then Bullock after halftime, as the Tar Heels returned to the form they displayed during a six-game winning streak before last weekend’s home loss to rival Duke.

“That was a terrible game for us offensively,” Bullock said of the Duke game. “We just came out and played great basketball.”

Two of Hairston’s first-half 3s fueled an 8-0 burst that gave UNC a 10-point lead, then Bullock sparked the 13-0 second-half run that helped the Tar Heels blow the game open.

“It seemed that we just could not keep up with Bullock and Hairston,” Seminoles coach Leonard Hamilton said. “Our game plan was to try defensively to be there, not allow them to get out in transition and get those open looks. They’ve got such great range and get it off so quick, that if you allow them to catch, contesting’s hard.”

After FSU closed to within 39-35, Hairston started the run with a 3, while Bullock followed two possessions later with his own 3 over Devon Bookert. Bullock also had a driving layup while drawing a foul for a three-point play, then Hairston closed the run with two free throws to make it 52-35 with 14:15 left.

Florida State never managed to get that deficit back to single digits.

Snaer — the senior with buzzer-beating winners in the past two seasons — fouled out with 1:40 left and headed to the bench to a standing ovation from his teammates.