TAMPA, Fla. -- Mike Krzyzewski was perplexed.

Through good and bad times, Duke has always been able to rely on an old ally at this time of year.

"We have not played well defensively for two weeks," the coach said Thursday night after an 85-80 overtime loss to North Carolina State in the first round of the Atlantic Coast Conference tournament.

"We've given up almost 90 points a game the last three games. We're just not going to win ballgames unless we play defense."

Freshman Brandon Costner scored a career-high 30 points and Engin Atsur scored all 21 of his after halftime, helping N.C. State pull off one of four upsets on the opening day of the league's signature event.

Duke (22-10) had won seven of the past eight ACC tournaments, including the past two. The 21st-ranked Blue Devils, seeded seventh, lost in the first round for the first time since 1997, while the 10th-seeded Wolfpack beat their rivals for only the third time in the last 23 meetings between the schools.

"We're not playing together on the defensive end of the court, and they took advantage of that," Krzyzewski said. "In the last two weeks, we're not communicating on defense. So guys are playing individually instead of collectively."

In other games at the St. Pete Times Forum, ninth-seeded Florida State defeated No. 8 seed Clemson 67-66, 12th-seeded Miami knocked off fifth-seeded Maryland 67-62 and No. 11 seed Wake Forest edged sixth-seeded Georgia Tech 114-112 in double overtime.

Top seed North Carolina faces Florida State, second-seeded Virginia takes on N.C. State, No. 3 seed Virginia Tech meets Wake Forest and No. 4 seed Boston College plays Miami in Friday's quarterfinals.

N.C. State (16-14) rallied from a 60-54 deficit in regulation and had four shots to win in the final 10 seconds. But Costner misfired on a short jumper in the lane, then Atsur and Courtney Fells missed 3-pointers before Atsur's desperation tip flew over the rim at the buzzer.

Costner got the Wolfpack off to a quick start in overtime, and N.C. State led 82-76 after Atsur, who was scoreless in the first half on 0-for-4 shooting, made a pair of free throws with 43.4 seconds left.

Martynas Pocius converted a three-point play to give Duke hope, but the closest the Blue Devils got after that was 83-80. Costner made two free throws to close out a victory that will help make an otherwise disappointing season bearable for the Wolfpack.

"As you all know, the rivalries are great on Tobacco Road, and nothing will make our fans and us happier than to beat Carolina and Duke," Costner said. "To succeed in beating them this year is a great accomplishment."

Greg Paulus led Duke with 18 points and Josh McRoberts and DeMarcus Nelson both scored 17. The Blue Devils fell behind 73-70 on Costner's three-point play in the opening minute of overtime and never fully recovered.

The loss was the third straight for the Blue Devils.

"I don't know if our team's gotten tired, gotten worn down," Krzyzewski said. "I know they're still working hard, but that can happen at the end of the year. We've tried to take care of that over the last couple of days, but what we attempted to do obviously didn't translate into us doing a better job."

Duke played without freshman Gerald Henderson, who served a mandatory one-game suspension for a flagrant foul that broke Tyler Hansbrough's nose during the closing seconds of a loss to North Carolina last Sunday.

Although Henderson only averages 6.8 points, he was most effective as a scorer in his past two games, with 15 against Maryland and a career-high 16 against North Carolina.

"He's a very important piece to their team," Wolfpack coach Sidney Lowe said. "He gives them the athleticism, he gives them rebounding, he gives them another guy that can score the ball and defend. Anytime you miss a player like that, it's going to affect your ballclub."

Miami 67, No. 17 Maryland 62

Jack McClinton scored 17 points and Brian Asbury added 12 for Miami.

Dwayne Collins had 12 points and 12 rebounds for the Hurricanes (12-19), who nearly squandered a 15-point lead in the second half, but McClinton and Asbury combined to make five consecutive free throws in the final 34 seconds to snap the Terrapins' seven-game winning streak.

Mike Jones led Maryland (24-7) with 15 points.

Florida State 67, Clemson 66

Al Thornton's free throw with 1.5 seconds remaining capped a 25-point, 11-rebound performance for Florida State.

Thornton, the ACC's leading scorer and runner-up for conference player of the year, carried the Seminoles (20-11) down the stretch. His block at one end of the floor denied Clemson what looked like a sure basket, then drove the baseline on the other end for a dunk that tied the game for the last time.

Trevor Booker had 18 points and nine rebounds for Clemson (21-10), which may have eliminated itself from NCAA tournament contention by losing for the 10th time in 14 games after starting season 17-0.

Wake Forest 114, Georgia Tech 112, 2OT

Harvey Hale scored 21 points after regulation for Wake Forest

(15-15), including five 3-pointers in the two extra periods.

He hit consecutive 3-pointers in the second overtime, one to tie it at 111 and another to give the Demon Deacons a 114-111 advantage with 26.5 seconds remaining.

Thaddeus Young led the Yellow Jackets with a career-high 30 points on 10-of-19 shooting.