Pettibone allowed two runs and six hits, striking out six in 5 1-3 innings. The righty was pulled after 83 pitches and didn't get a decision.
Pedro Alvarez and Russell Martin hit solo homers for the Pirates.
On a chilly night when the temperature dipped below 50 degrees, the Phillies scratched out their second straight win to improve to 9-11.
Pirates starter A.J. Burnett gave up two runs and five hits, fanning seven in five innings. Jared Hughes (1-2) retired the first two batters he faced in the sixth before running into trouble.
Hughes walked Erik Kratz. Pinch-hitter Ezequiel Carrera then reached on an infield single, diving headfirst into first base. Rollins followed with a line-drive single to right that scored Kratz.
Raul Valdes (1-0) got two outs in the sixth to earn the win. Antonio Bastardo worked the seventh, Mike Adams tossed a perfect eighth and Jonathan Papelbon finished for his fourth save in four tries.
Garrett Jones hit a one-out double off Papelbon, but Neil Walker flied out to right and Papelbon struck out Alvarez looking to end it. Papelbon is 55 for 55 in save chances in April in his career.
Filling in for injured lefty John Lannan, the 22-year-old Pettibone was called up from Triple-A Lehigh Valley after going 0-2 with a 9.20 ERA in three starts.
He fared better against big league batters.
Alvarez gave the Pirates a 1-0 lead when he drove his third homer out to right in the second. Martin led off the fifth with a drive out to left to tie it at 2.
Pettibone helped Philadelphia get its first run when he walked in his first plate appearance in the third, advanced to second on Rollins' single, went to third on a grounder and scored on a wild pitch.
The Phillies briefly took a 2-1 lead in the fourth. Michael Young led off with an infield single, extending his hitting streak to 13 games. Domonic Brown walked and Ben Revere singled to load the bases.
Burnett struck out Kratz following a 10-pitch at-bat and fanned Pettibone.
But Rollins took a 2-2 pitch off his leg to force in a run. Burnett then struck out John Mayberry Jr. to end the inning.
Pettibone worked out of trouble in the first after Starling Marte led off with a double and advanced to third on a fly out. He fell behind Andrew McCutchen 3-0 before striking him out looking at a fastball on the outside corner. Mayberry then saved a run with a fully-extended, diving catch on Jones' liner to right.
NOTES: Pettibone was 13-8 with a 3.10 ERA in 26 starts last year at Double-A and Triple-A. ... Phillies C Carlos Ruiz is expected to play for Class-A Clearwater on Tuesday. An All-Star last year, Ruiz is suspended for the first 25 games for testing positive for an amphetamine. He can play five minor league games before suspension ends. ... The Pirates extended their errorless streak to 40 innings. ... Phillies opening-day starter Cole Hamels (0-2, 6.46) tries again for his first win on Tuesday night vs. LHP Jeff Locke (1-1, 5.17).