RALEIGH, N.C. -- North Carolina turned tough again when it counted.

The Tar Heels were steady down the stretch in a strong second half in advancing in the NCAA Tournament.

Forward Brice Johnson scored 21 points and North Carolina clamped down on foul-plagued Providence to run away with an 85-66 victory in the in the second round Saturday night at PNC Arena.

"These guys were tough-minded the last 18 minutes," Tar Heels coach Roy Williams said. "The second half, they score the first six points and then I thought we were really good."

North Carolina (30-6), the top seed in the East Regional, plays Indiana in the Sweet 16 on Friday night in Philadelphia. It advanced to the round of 16 for a record 26th time.

The Tar Heels reached 30 wins for the 12th time. Six of those have come in 13 seasons under Williams.

The latest accomplishment came with some lock-down defense that allowed the margin to balloon.

"We tried to make everything as hard as we possibly could," forward Justin Jackson said of defending the Friars. "The defensive effort is all that it takes for us. When we can play as hard as we can on defense, that's when we're at our best."

Guard Joel Berry (15 points), forwards Jackson (15 points) and Isaiah Hicks (13 points) and guard Marcus Paige (12 points) contributed to North Carolina's balanced attack.

Johnson said the Tar Heels thrived after they were challenged in the first half. They were cheered on by a highly partisan crowd.

"I've got to step up in a big-time game," Johnson said.

That's something that Williams said he has noticed beginning with the last week of the regular season.

"I started appreciating this team (for that)," he said.

Guard Kris Dunn scored 29 points for ninth-seeded Providence (24-11). Forward Ben Bentil, the team's leading scorer, fouled out with 7:23 remaining after scoring 21 points on 7-of-17 shooting from the field.

"We got in foul trouble," Dunn said. "They took advantage of that and made a couple of runs."

Bentil had a tall task tangling with North Carolina's interior players.

"They just made good plays," he said. "They played better today."

Aside from Dunn and Bentil, the three other starters for the Friars combined for four points. Forward Rodney Bullock, who made the winning basket two nights earlier against Southern California, was 0 of 7 from the field and ended up with two points.

Providence scored the first six points of the second half to go ahead at 36-34.

With the score tied at 41, the Tar Heels scored the next nine points.

Paige had five consecutive points during another key juncture as North Carolina was on the way to building a 57-48 edge.

Dunn found some satisfaction in the season as a whole.

"The fact that we got passed the first round was one of the accomplishments I wanted to achieve," he said.

The Tar Heels used a 9-0 run late in the first half to secure a 34-30 advantage at halftime.

Providence didn't connect on a field goal in the final 5:50 of the half, but two free throws from Bullock thwarted some of North Carolina's momentum.

North Carolina took the ball inside, accounting for 18 of its first 21 points in the paint. The other three points came on Paige's long-range 3-pointer.

A 21-14 lead for the Tar Heels was wiped out by Providence's 8-0 run. That came with Dunn on the bench with two fouls.

Dunn had 10 points at the half but sat out for about 11 minutes. Paige also had two fouls, missing eight minutes.

NOTES: North Carolina won three of the four previous meetings with Providence. These teams met in their NCAA Tournament opener in 2014, with North Carolina winning 79-77 in San Antonio. ... North Carolina has a 29-game winning streak in NCAA Tournament games played in the state of North Carolina. ... Providence was coming off its first NCAA Tournament victory since winning three games in 1997. That year, the first two victories also came in North Carolina, with the Friars capping their visit to Charlotte by upsetting Duke. ... This was North Carolina's first game since coach Roy Williams moved alone in second place on the NCAA Tournament wins list with 66. ... Providence went into the game needing one more victory to reach the 25-win total for the first time since the 1987 Final Four team.