UNC used an 8-0 run to finally push ahead for good, with Kennedy Meeks coming up with some key plays despite being limited by a recent illness. The Tar Heels then went 6-for-6 at the line in the final minute to seal it and earn a date with No. 3 Virginia in the semifinals.
Terry Rozier scored 20 to lead the fourth-seeded Cardinals (24-8), who shot just 8-for-36 (22 percent) after halftime - including a 5½ minute drought that tipped a tight contest toward UNC.
Louisville missed 15 of its last 17 shots, a remarkable turnaround considering the Cardinals shot 52 percent in the first half and appeared to have early control. And the Cardinals finished just 4-for-22 from 3-point range in its ACC tournament debut.
Just as with the previous matchups, this one was another fight - and in all three games, the winning team overcame a double-figure deficit.
Meeks had missed the UNC's ACC tournament opener because of illness and a fever, which caused him to miss two practices. He looked like he was laboring through much of his court time, only to muscle in a shot over Mangok Mathiang and follow with a stickback to cap UNC's 8-0 run to a 64-57 lead with just under 4 minutes left.
He followed that by blocking a baseline drive by Rozier.
Louisville: Montrezl Harrell had 14 points and 12 rebounds. ... Wayne Blackshear added 18 points and three 3-pointers. ... Louisville finished with a 15-10 edge on the offensive glass, but scored just eight second-chance points.
UNC: Justin Jackson added 10 points. ... UNC shot 50 percent after halftime. ... Freshman Theo Pinson missed his second straight game due to soreness in his left foot. He had recently returned from a monthlong absence after breaking that foot in late January.
UNC will play top-seeded Virginia on Friday night.