The win put the Tar Heels in a first-place tie with Virginia. Carolina has followed each of its four losses this season with a road victory over a ranked team.
"We're a pretty darn good team on the road," Tar Heels coach Roy Williams said. "I love it. I really do. I love going on the road and quieting the crowd."
Playing at Boston College, a newcomer to the ACC, rarely presents the problems Williams might expect from a visit to Duke or Maryland. But an unusually raucous crowd greeted the Tar Heels (23-4, 9-3) for their first-ever visit to Chestnut Hill.
Spurred on by their yellow-clad supporters, BC (18-8, 9-4) came within three points twice in the final minutes.
But Jared Dudley missed all three free throws after he was fouled trying a 3-pointer with 1:29 left. He also missed a 3 when it was 75-72 with 10 seconds left, and Ty Lawson hit a pair of free throws with 7 seconds remaining to ice it.
"You can't make every shot," said Dudley, who scored 22 points despite missing the final six minutes of the first half after picking up his third foul. "I'm disappointed in myself, but you had the opportunities. Hopefully, the next time I get the opportunity I'll knock them down."
Even Williams noted Dudley's plight.
"I feel for him, missing the free throws like that," said the opposing coach, who improved to 1-2 against the Eagles in his career. BC was the only team Williams had coached against more than once without beating.
Lawson finished with 13 points, seven assists and six rebounds for Carolina. Brandan Wright scored 13 with three blocked shots as North Carolina bounced back from Tuesday night's 81-80 overtime loss to Virginia Tech.
Tyrese Rice had 20 for the Eagles, who lost to Duke on Wednesday night. BC was 0-for-10 from 3-point range in the second half and 3-for-9 from the line in the final 5:31.
"We had some opportunities on the free throw line, and we got the shots we wanted. We just didn't make them," BC coach Al Skinner said. "Some nights they just don't go. I can live with that, I really can. ... We did the hardest part, and that's what I'm most pleased about."
The Tar Heels led by as many as nine in the second half before BC tied it 61-all on Dudley's drive. Reyshawn Terry, who scored all of his 10 points in the second half, hit a 3-pointer to put North Carolina back ahead to make it 73-66 with 3:49 left.
Dudley hit two free throws and Rice made a foul-line jumper as the shot clock expired to cut it to three points. But Dudley missed his foul shots and BC missed its best chance to beat a traditional ACC power from North Carolina.
On Wednesday, Duke brought a four-game losing streak to Chestnut Hill and won 78-70. The crowd never had a chance to get excited against Duke, thanks to a snowstorm and a first-half double-digit deficit.
But North Carolina attracted an atmosphere typical of the ACC but rarely seen in the Heights, with most of the crowd wearing yellow T-shirts _ even former Heisman Trophy winner Doug Flutie _ and the student sections standing the entire game.
They saw BC stay close for most of the first half, fighting back from a 24-16 deficit to take a 26-25 lead on Dudley's 3-pointer with 6:57 left. But after the teams traded baskets and leads, Dudley picked up his third foul and went to the bench for the last 6:03 of the half.
Without him, BC fell behind 44-38.