Connaughton came up with a pair of 3s during Notre Dame's go-ahead run, with the Irish getting into a fast-paced, free-flowing attack set loose by a few ill-timed turnovers by the Tar Heels (24-11).
When it was over, Notre Dame had turned a 63-54 deficit into an 80-66 lead on Connaughton's dunk with 2:54 and largely silenced a home-state UNC crowd featuring plenty of blue in the Greensboro Coliseum seats.
Notre Dame had reached the final with an upset of No. 2 Duke in Saturday's semifinals. Coach Mike Brey said afterward "there would be no greater achievement in the history of our program" than to complete the title run, joking - or maybe not - that they would have to put an asterisk by it if they beat both Duke and North Carolina in their home state to do it.
When the horn sounded, Brey walked right to Grant and hugged the all-ACC guard as players spilled onto the court to celebrate. Grant was selected the tournament MVP.
Marcus Paige scored 22 of his 24 points after halftime for the fifth-seeded Tar Heels, who were trying to become the first team in tournament history to take home the title with four wins in four days.
Instead, as Notre Dame found its groove and started burying shots from just about everywhere, North Carolina suddenly looked lost.
Notre Dame shot 54 percent, made 10 of 20 3-pointers and hit 28 of 32 free throws to keep the pressure on the Tar Heels' defenders.
UNC shot 58 percent after halftime, but just couldn't keep up once Notre Dame got rolling.