Diamond DeShields scored 21 points to lead the Tar Heels (17-4, 5-2 Atlantic Coast Conference), who had 18 of their 29 turnovers in the second half.
Brianna Butler scored 22 points and Brittney Sykes had 17 points for the Orange (16-5, 5-3), who trailed 50-32 with 18 minutes remaining. Briana Day scored 11 points for Syracuse.
Butler scored 17 points in the second half, including a 3-pointer that put her team ahead 72-69 with 2:42 remaining.
After a North Carolina turnover, Sykes hit a jumper to give the Orange a 74-69 lead with 2:05 to play.
The Tar Heels pulled to 74-71 on a putback by Allisha Gray, but Butler answered with a jumper to seal the game.
Stephanie Mavunga and Gray each had 16 points for North Carolina.
North Carolina hosts Miami on Sunday at 2 p.m., on the Regional Sports Network and ESPN3/WatchESPN. The 1994 Tar Heel national championship team will be honored at halftime, marking the 20th anniversary of the title.