North Carolina (15-15) will take on sixth-seed Syracuse in the second round on Thursday at 8 p.m.
Kauai Bradley led Pitt (13-17) with 12 points, while Kalista Walters and Brenna Wise had 11 points each and Jasmine Whitney had 10.
The win snapped a snaps three-game losing streak to Pitt, including an 82-72 overtime setback in the first round of this tournament last season.
Carolina limited the Panthers to only 19 points after halftime, and grabbed more rebounds, 38-30, than its opponent for the first time since Jan. 8 against Virginia.
A 10-0 run to begin the third period lifted the Tar Heels into the lead after trailing 41-37 at intermission. Koenen opened with a triple and Cherry matched that with one of her six three-pointers to give UNC the lead for good.
Cherry iced away the win with free throws in the final three minutes, nine seconds of the fourth quarter. She has scored 20 or more points in seven of her last 10 games.
Cherry scored 16 points in the first half, and Pitt’s Kauai Bradley scored 12. Pitt shot nearly 55 percent from the floor in the first 20 minutes, and UNC shot 50 percent.