CHAPEL HILL — The ACC has another national-title contender, and it isn’t the defending national champions.

Duke still has a shot, even after the Blue Devils couldn’t keep up with North Carolina on Saturday, but the Tar Heels showed just how far they have come -- from last season, from a lackluster stretch to open this season and from last month’s loss to Duke in Durham.

Throw out a baffling loss to Georgia Tech, and the Tar Heels have spent two months getting better, culminating in an authoritative 81-67 win over Duke. The team that lost in the third-place game in Puerto Rico finished atop the ACC -- and has just as much of a chance to make a long postseason run as Duke.

The Blue Devils will have the higher NCAA seed, based on a more impressive overall resume, but there may not be anyone playing any better than the Tar Heels right now. There certainly is not in the ACC.

“A buddy told me I’ve gotten a lot smarter the last couple weeks,”North Carolina coach Roy Williams said. “I didn’t get any smarter, but my team got better. I said in November this was a team that was going to keep growing and getting better.”

If the Tar Heels’ growth needed underlining, consider a Senior Night ceremony oddly devoid of signature moments to recognize, without a single four-year scholarship senior on the roster and would-be honoree Will Graves playing in Japan.

This very young team has come a very long way, with Harrison Barnes shaking off those early growing pains to become as clutch a player as there is in the ACC, John Henson flourishing in the post and Kendall Marshall taking over, period. Even Tyler Zeller admitted he wasn’t sure, a few months back, that the Tar Heels could come this far, this fast.

“Possible? Yes,” Zeller said. “Chances weren’t very high. It was one of those things where we had the talent, we had the ability, but at that time we weren’t playing nearly as good defense or offense as we are now.”

While Larry Drew II is busy planning to celebrate his 21st birthday Monday with Jamie Foxx, Marshall celebrated the ACC regular-season title Saturday night with the students who stormed the court.

Among his 15 points, 11 assists and two turnovers, he spun past Tyler Thornton for a lay-in, a moment of individual brilliance that secured a spot in all those sepia-toned montages of Great Plays in the History of the Rivalry.

“I think they’re really good,” Duke coach Mike Krzyzewski said. “I said that after we beat them in Cameron. I told you, I think they’re as good a team as we’ve played. That hasn’t changed for me.”

Krzyzewski also said the Blue Devils need to play better than they did to beat North Carolina, and Duke left its biggest weaknesses exposed Saturday: A soft middle and limited depth, both personified by Ryan Kelly’s struggles.

These are not necessarily fatal faults. Duke looked similarly vulnerable in a loss to Georgetown last January and the Blue Devils went 18-1 afterward to win the ACC and NCAA tournaments. They still have the ACC’s best player in Nolan Smith, and if the Tar Heels are ahead, it’s not by much.

But as the regular season wound to a close Saturday, the Tar Heels demonstrated they had not only closed the gap on Duke but the rest of the country as well -- and without a dominant team out there, they have the same chance to win it all as the Blue Devils, this year or last.

luke.decock@newsobserver.com, twitter.com/LukeDeCock or (919) 829-8947