North Carolina had thrived after switching to a four-guard lineup that spread the floor and relied on the 3-point shot. The Tar Heels just couldn't hit much of anything when it came time to face their biggest rival Saturday night.

North Carolina missed its first 11 3-point tries and finished 1-for-14 from behind the arc in the 69-53 loss to third-ranked Duke. It was a big step back for a team that had gone 6-1 since making P.J. Hairston a starter in a smaller lineup while rebuilding some confidence that looked lost a month earlier.

"We can't dwell on it," senior Dexter Strickland said. "We can't let this shoot our motivation down or our confidence down."

Before Saturday, the Tar Heels had been shooting almost 41 percent from 3-point range with the new lineup, while their attempts had crept up from around 19 to 21 per game. In fact, the switch came in the first meeting with Duke and helped the Tar Heels take the Blue Devils to the final minute in hostile Cameron Indoor Stadium.

But on Saturday, UNC looked too willing to settle for jumpers and stopped utilizing those driving lanes that had developed in recent games.

"It's not a very good feeling," UNC coach Roy Williams said. "I don't want this game to define what this team has done. This team has done some good things. ... We get to play again. That's what they have to focus on and make sure this doesn't define what this team is."

For Duke, Seth Curry hit his first seven shots during Duke's torrid start and finished with 20 points.

Fellow senior Mason Plumlee turned in his best performance in a month with 23 points and 13 rebounds. That duo provided Duke (27-4, 14-4 Atlantic Coast Conference) all the punch it needed to earn a season sweep of the Tar Heels.

Duke scored the game's first 14 points, never let UNC (22-9, 12-6) closer than nine and led by 25 points after halftime. The Blue Devils shot 55 percent, including 18 for 26 (69 percent) in a first half that silenced a once-rowdy Smith Center crowd and overwhelmed the once-surging Tar Heels.

James Michael McAdoo finished with 15 points to lead the Tar Heels despite playing with a bulging disk in his back, but the rest of his teammates did little to help him.

Hairston finished with 14 points on 4-for-12 shooting and hit the Tar Heels' only 3 to cut the deficit to 63-49 at the 5-minute mark. But Quinn Cook answered with two driving baskets, the second a hanging shot at the rim that dropped through as the shot clock expired and took back any fleeting momentum North Carolina had built.

In fact, the game looked a lot like last year's regular-season finale at Cameron Indoor Stadium, where the Tar Heels jumped all over the Blue Devils early on the way to a blowout win.

In each of the past two seasons, Duke had won the first meeting only to have UNC win the second to clinch the ACC regular-season title.

That story line was off the table this time. Miami took care of that by beating Clemson for the outright title earlier Saturday. Duke had already clinched the No. 2 seed for the conference tournament, while North Carolina State's loss at Florida State meant the Tar Heels would be the No. 3 seed but could still tie Duke for second in the standings.

Instead, Curry and the Blue Devils came out with a shooting display that ran North Carolina right out of the Dean Dome by halftime in a performance that will resonate until next week's league tournament in Greensboro.

Not to mention it turned the latest renewal of the famed rivalry into a colossal dud.

Curry made one 3, hit a scooping layup and banked in a runner during Duke's 6-for-6 start that helped the Blue Devils to a football-esque 14-0 lead.

And he didn't stop, either.

Curry nailed a tough jumper against Reggie Bullock. He lost Bullock to drain another shot. He hit one even as he fell backward to the floor, the kind of play that eliminates any doubt about whose night it's going to be.

After Curry made his seventh straight shot, Williams practically wandered out near midcourt to shout at his players as they ran down on offense.

Curry finished 8 for 13 and Plumlee took over inside by making 10 of 15 shots against the Tar Heels' undersized frontline.

Cook added 12 points and completely outplayed UNC freshman point guard Marcus Paige, who regressed from his recent strong play with four points on 1-for-6 shooting and five turnovers in 32 minutes.