TALLAHASSEE, Fla. -- It will be a while before Florida State fans forget Harrison Barnes.
The 18-year-old North Carolina freshman coolly hit a 3-pointer from the top of the key with 3 seconds to play that gave the 13th-ranked Tar Heels a 72-70 victory and silenced a boisterous Seminole crowd.
"Great players make great plays," Florida State coach Leonard Hamilton shrugged. "That's about as good as it gets."
But it wasn't anything unusual for Barnes, who has made the game-winning or go-ahead shot in five games this season.
"I've always been comfortable taking the last-second shot," said the soft-spoken Barnes, who is from Ames, Iowa. "I'm glad Coach gave me the opportunity and I came through."
Barnes was supposed to drive to the basket, but decided to pull the trigger from long range after he briefly surveyed the defense.
"They had three guys high so I knew it was going to be a jump shot, because it would be hard to get to the rack," he said.
"You can't really second-guess yourself," Barnes said. "You have to go with the first instinct."
Florida State's Michael Snaer blamed himself for letting Barnes get a solid look.
"I just gave him too much breathing room," Snaer said.
John Henson had 19 points and 12 rebounds and Barnes added 18 points for the Tar Heels (23-6, 13-2 Atlantic Coast Conference), who won their sixth straight game overall and their fifth in a row on Florida State's court.
North Carolina took the lead midway through the second half and was up 67-60 on Kendall Marshall's 3-pointer with 3:59 left. Florida State rallied to take a 70-69 lead with 18 seconds left on two free throws by Derwin Kitchen, who led the Seminoles (20-9, 10-5) with 13 points.
"We certainly gave them some opportunities and they took advantage," North Carolina coach Roy Williams said.
Florida State turned the ball over before getting off a final shot after Barnes' game-winner.
The Tar Heels can clinch the top seed in next week's ACC tournament win a win over No. 4 Duke on Saturday. Florida State finishes its regular season Sunday at North Carolina State.
Leslie McDonald added 10 points for North Carolina, including two 3-pointers 43 seconds apart that gave the Tar Heels a 49-44 lead with 14:18 left.
Snaer added 11 points and Bernard James had 10 for the Seminoles, who were without top scorer Chris Singleton (broken right foot) for the fourth straight game.
Florida State led 38-37 after a first half that saw both teams shoot 16 of 31 from the field and had nine lead changes and nine ties.
Henson, a 6-foot-10 sophomore from Tampa, had a big first half with 12 points, six rebounds and three blocked shots while Florida State answered with strong play from its bench players, who outscored the Tar Heel reserves 20-5.
North Carolina shot 47.3 percent for the game and had a 39-28 rebound advantage.
One of those Seminole backups, freshman Ian Miller, nailed a 3-pointer from the corner midway through the first half that gave Florida State its largest lead of the game at 26-19.
Florida State was attempting to finish a perfect ACC season at home for the first time since coming into the conference for the 1991-92 season.
Barnes had 17 points and 10 rebounds in the Tar Heels' 89-69 home victory over Florida State 24 days ago.