The Tar Heels (12-1-1) won their eighth game win a row and remained unbeaten in the ACC at 5-0-0.
UNC dominated the first half, but BC keeper Jillian Mastroianni thwarted the Heels. BC went ahead on a goal by sophomore Gina DiMartino scored with a looping hot in the 51st minute.
Carolina went ahead on goals by Casey Nogueira (her sixth in the last three games and 13th on the season) and Allie Long. Eight minutes after Long's goal, the Eagles tied the game on Natalie Crutchfield's goal.
Sophomore Meghan Klingenberg picked up her second assist of the game when she fed Bartok with the winning goal on a patented long ball to the far post.
Elsewhere in the ACC ...
-- No. 7 Virginia suffered its first loss in ACC play this season, falling to Virginia Tech 1-0 Thursday night on Julian Johnson's goal just after halftime.
"Give Virginia Tech credit, they deserved to win," said Cavs coach Steve Swanson. "We didn't come out with the same energy level as we have had in recent games and we paid the price for it."
-- No. 12 Duke gained a key ACC victory on Thursday evening with a 3-1 win over No. 20 Wake Forest. Goals on either side of halftime by Kelly Hathorn and Elisabeth Redmond gave the Blue Devils a 2-0 lead. Redmond extended the lead with a penalty kick in the 65th minute before U.S. U-20 Kaley Fountain scored a consolation on a rocket from 15 yards out.
"I think it was a great performance in the sense that we struggled earlier in the match, we made some adjustments; we moved some players," said Duke coach Robbie Church. "Players off the bench, they did a great, great job. The depth in those players was really big time. Kelly's [Hathorn] been around the goal all year. We knew it was coming. She just had to stay in there and keep working, and she scored a huge goal -- the first goal was going to be big in this game."