Paige and Johnson combined to score 10 points during the 12-0 run that finally gave the Tar Heels some cushion midway through the second half against the Crusaders (1-2), who hung tough despite a miserable shooting game.
Malachi Alexander scored 13 to lead Holy Cross, which shot 29 percent and missed 17 of 22 3-pointers.
Paige and Johnson turned in their second straight strong performance to start the year. With Hairston and McDonald out, that's meant more minutes for Paige on the wing instead of his normal role at the point. He scored 14 points with four 3-pointers in the opening win against Oakland a week earlier, then went 8 for 17 from the floor with three 3s in 36 minutes Friday.
He also hit four free throws in the final minute to help seal the win, including two with 58.5 seconds left after Holy Cross had clawed to within 56-50.
Johnson, a lean 6-foot-9 forward, showed a nice touch in the paint to give the Tar Heels some needed interior scoring when they were struggling with their own shooting. Johnson went the last 21 games of his freshman season without reaching double figures, but has done it in two straight games to open the year.
North Carolina shot just 27 percent (9 for 33) in the first half, but shot nearly 52 percent after halftime to finally take control.
Holy Cross was coming off a 122-118 double-overtime win against Sacred Heart on Wednesday, when the Crusaders knocked down 11 3-pointers and got a combined 61 points from Cullen Hamilton and Dave Dudzinski. But those shots just wouldn't fall against North Carolina, keeping the Crusaders from pressing the Tar Heels for a possible upset.
Dudzinski finished with 11 points on 4-for-12 shooting, while Hamilton had eight on 2-for-11 shooting.
North Carolina led 11-1 early as Holy Cross misfired on 16 of 18 shots to open the game. But the Tar Heels struggled with their shooting just as much, squandering a chance to build a big lead as the Crusaders crawled their way into a 25-all tie just before halftime.
The teams shot a combined 15-for-60 (25 percent) in that opening half.