Mayberry finished 3-for-4, including a go-ahead, two-run double in the fourth inning.
Kevin Frandsen and Domonic Brown each belted a solo homer for the Phillies, who took the opener of a two-game series.
Pettibone (3-0) remained undefeated in his fifth major league start, holding the Indians to two runs on four hits over 6 2/3 innings. He walked two and struck out three.
Tribe starter Scott Kazmir (2-2) was touched for four runs on six hits over five full frames.
Michael Brantley drove in both Cleveland runs.
Benedict Cumberbatch's dramatic reading of R. Kelly lyrics is just what you need
Jordana Brewster on Paul Walker: 'He was an enormous presence in my life'