After Rashad McCants double clutched a game tying three-pointer with 13.5 seconds remaining in the extra period, Blue Devil guard Chris Duhon drove down the left sideline and then cut across the lane for a layup ending the Tar Heels dramatic upset bid.
"On the last play, Coach [Krzyzewski] called out for me to go, so I went," Duhon said.
"It was a situation where David [Noel] and I ran into each other a little bit and David thought that I was going to get back on Duhon," Raymond Felton said.
McCants scored 27 points, Felton dished out eight assists and Sean May pulled down 21 rebounds to lead UNC, which must immediately get ready for a 1 p.m. tip off at Wake Forest.
May, who returned to form with 15 points to go with his career-high tying rebound total, suffered from cramps down the stretch.
"Man it hurts; I've never felt this bad after a game in my life," May said. "At the end I wanted to be out there so bad."
The Tar Heels (13-6, 3-5 ACC) continue to struggle closing out games, blowing a seven-point lead late in regulation.
"We are the best team in the country by far," said McCants, the ACC scoring leader who has scored 26 or more points in five of his last six games. "The reason we are losing is because we can't figure out how to take advantage of games. We're beating ourselves.
"I really think we needed this game as a springboard for going into the second half of the ACC season, but I think it still is because we lost and I know we should have won."
A circus baseline basket and three-pointer from Felton, followed by a breakaway slam by McCants gave Carolina its biggest lead of the night at 69-62 with 5:44 left in regulation. But the Blue Devils then capitalized on three consecutive Tar Heels' turnovers to pull within one and later led 74-71 with 38.3 seconds showing on the Smith Center clock.
"It was just mental mistakes; turnovers when we had the lead," Felton said. "We should have won that game."
However, there was still plenty of late-game heroes on both teams. Despite tenacious perimeter defense, Jawad Williams found just enough room to get off a game tying three with 18.3 seconds remaining, eventually forcing overtime with the score tied at 74-74.
Duke (19-1, 8-0 ACC) was led by Shelden Williams' 22 points and 12 rebounds. Daniel Ewing hit 4-of-9 threes on his way to 19 points and Luol Deng registered a double-double with 17 points and 12 rebounds.
"The game was an unbelievable fight between two unbelievable teams," Deng said.
Both teams were 15-for-30 from the field in the opening period, but the Blue Devils parlayed a slight rebounding edge and one more 3-pointer than the Tar Heels into a 42-37 lead at halftime. Shelden Williams scored 14 points before intermission, while May had 11 rebounds before the break.
"There were just a lot of great performances tonight," Krzyzewski said. "I don't think there has been a game this year that matched the energy level of both teams."
The Tar Heels are now 7-6 after beginning the season 6-0.
"I've been critical of our defense and I've been critical of our work ethic, but I'm extremely proud of our team tonight," UNC coach Roy Williams said. "We played exceptionally hard. It was a big-time college basketball game and I'm tired of coming out on the short end."
"Coach is a great man because he takes all of the blame," May said. "He's in that locker room and he's hurt right now, because he's trying to find a way for this team to play the way he knows we should be playing. It's about time that we start becoming accountable for our own mistakes."