North Carolina (20-9, 10-6 Atlantic Coast Conference) reached 20 victories for the 11th time in 12 years under coach Roy Williams. Miami (18-11, 8-8) lost at home for the sixth time this year, and lost to North Carolina for the first time since 2012.
The Tar Heels had lost five of their previous seven games, and played like a team desperate to turn things around. Marcus Paige had 15 points, while J.P Tokoto had 10 points, 10 rebounds, six assists and four steals for North Carolina.
That gave fans clad in blue plenty to cheer about. They made up a sizable portion of the crowd of 7,972.
Miami guard Angel Rodriguez, nursing a right wrist injury, was held out of the starting lineup for the first time this season and played only three minutes. Backcourt mate Sheldon McClellan, the Hurricanes' leading scorer this season, was limited to 25 minutes because of foul trouble and had 11 points.
Miami trailed only 57-54 with five minutes to go, but dunks by Johnson on consecutive possessions helped the Tar Heels pull away. Those scores came during an 8-0 run that put them up 65-54.
The Hurricanes missed five consecutive shots during their decisive drought. They shot only 43 percent, including 6 of 23 from 3-point range.
The Tar Heels raced to a 15-6 lead, their largest of the first half. They subsequently went nearly five minutes without a point, committing four turnovers during the drought as Miami closed to within 22-21.
Tokoto twice made a steal and dunk in the first half to help North Carolina lead 32-30 at halftime.
Ivan Cruz Uceda sank 3-points on consecutive possessions to put give the Hurricanes their only lead of the second half, 48-47.
North Carolina: Swingman Theo Pinson and guard Luke Davis were in uniform but didn't play. Davis has been sidelined all season with a broken right foot. Pinson has been out since Jan. 21 with a broken left foot.
Miami: Tonye Jekiri, who leads the ACC in rebounds, had seven in the first half but none in the second half. The Hurricanes were outrebounded 42-28.
North Carolina plays at Georgia Tech on Tuesday.