Simon Gagne scored two goals and added two assists, Peter Forsberg had four assists, and Antero Niittymaki stopped 15 of the Penguins' 20 shots as the Flyers improved to 2-2, while dropping the still winless Penguins to 0-2-3.
Philadelphia, which built an early four-goal lead, pelted the Pittsburgh goal with 41 shots, but could not thwart a Pittsburgh comeback.
Sidney Crosby had a goal and an assist, John LeClair added a goal, both Mario Lemieux and Ric Jackman had two assists, and Andre-Marc Fleury and Sebastien Caron combined for 35 saves for the Penguins. In relief, Caron made 19 stops after Fleury allowed four early tallies.
Philadelphia was 2-for-8 on the power play, while Pittsburgh went 2-for-6.
It was the Penguins' fourth straight overtime contest.