The Blue Devils (22-2, 9-1 Atlantic Coast Conference) trailed 43-27 in the final minute of the first half and were down 14 at halftime before clamping down on the Tar Heels, outscoring them 50-30 in the final 20 minutes to match the second-best halftime rally in school history and keep hold of first place in the league.

"It wasn't an X-and-O adjustment. ... They were too excited," Krzyzewski said. "''Nuts' is the word. 'What are you guys doing?' It's not like, 'You know, you guys aren't playing hard.' They're playing hard. ... When you go like that, you're not coordinated, and it was more to get a coordinated effort on the offensive and defensive ends."

Tyler Zeller had 24 points and a career-high 13 rebounds, and John Henson added 14 points for North Carolina (17-6, 7-2), which had its five-game winning streak snapped and lost for the third straight time in college basketball's fiercest rivalry.

"To say it's extremely disappointing would be an understatement," North Carolina coach Roy Williams said.

Kyle Singler finished with 10 points on 3-of-17 shooting for Duke but hit three important free throws in the final minute -- including two with 25.2 seconds left to make it 75-70 after North Carolina had pulled within one possession.

Then, after Kendall Marshall hit a free throw to pull the Tar Heels within four with 17.2 seconds left, Smith beat everybody downcourt and soared for a breakaway dunk that sealed it, ensuring the Blue Devils would avoid their first loss at Cameron Indoor Stadium in almost two years and sending the storied arena into delirium.

Duke extended its NCAA-best winning streak at home to 33, and Smith called this one -- and not last April's victory over Butler for the program's fourth national championship -- the biggest of his career.

"This comeback win, how tough we were, how together we were and how great it feels now, I don't think anything can be better than this," Smith said.

Smith finished 13 of 23 and surpassed his previous career high of 33 points set a month ago against UAB. Curry hit two free throws in the final seconds to push his total past the 20 points he scored Jan. 27 against Boston College.

They teamed to help the Blue Devils deliver a comeback for the ages: Duke hadn't erased a halftime deficit that big to win since 1959, when the Blue Devils beat Navy after trailing by 14 at the break.

"The main thing was, Seth started to get hot and hit a lot of shots," Marshall said. "We just weren't getting around screens and on the shot fakes, they kept getting us up in the air. It's just little things like that, that when you're ahead, you can't forget about those things that got you ahead. And they jumped out on us."

The Blue Devils were in the unfamiliar position of being dominated at home when their guards got things rolling in the final seconds of the first half, with Curry's jumper at the 5-second mark starting the 18-6 run that made it a game again.

"We had to come out with a different mindset that we were going to fight," Curry said. "In the first half, they just beat us to every ball and every rebound. We were just running around and weren't really poised out there. In the second half, we came out, really calmed down and tried to get it back one possession at a time."

Smith's jumper from the elbow pulled Duke to 49-45 with 14½ minutes left, about 4 minutes before Curry started the 13-1 run that put the Blue Devils up for the first time.

Curry reeled off seven quick points in little over a minute before Ryan Kelly delivered the game's only lead change. His 3-pointer put Duke up 57-55 with 9:15 left, and Smith's three-point play roughly a minute later stretched it to 60-55.

Nobody on North Carolina's reconstituted roster had ever played in a victory at Cameron -- a 180-degree reversal from Feb. 11, 2009, when Tyler Hansbrough and Danny Green won for the fourth time in four trips to Duke while handing the Blue Devils their most recent loss at home.

North Carolina freshman Harrison Barnes, who said he took his official recruiting visit to Duke for that game, finished with nine points on 3-of-8 shooting to snap a run of seven straight double-figure games while hearing it all night from the Cameron Crazies. Marshall, who took over at point guard following the abrupt departure last week of Larry Drew II, had six assists and one turnover but was just 3 of 11 from the field.

Still, for essentially the entire first 20 minutes of this one, it was North Carolina that was in complete command.

The Tar Heels never trailed during the first half, reeled off the first eight points and methodically stretched their lead to 16 on Zeller's stickback 1:10 before the break. They did it largely by outworking the Blue Devils -- beating them downcourt with regularity, with the big men dominating the paint. By halftime, Zeller had 13 points and nine rebounds while Henson added 10 points.

"We just lost mental focus on the things we're supposed to do, especially with them boxing out and holding them to one shot," Henson said. "And that really catapulted them back in the game. So we've got to learn from this. It hurts so much because we had them by the neck and we let them get back in it."