Philadelphia trailed 3-1 late in the second period but reeled off the next four goals to improve to 4-1 on a six-game road trip.
Voracek's goal came after Wayne Simmonds had notched the equalizer 4:22 into the third period.
Steve Mason got the win with 26 saves.
Mikkel Boedker, Rob Klinkhammer and Lauri Korpikoski each scored for the struggling Coyotes, who fell for the eighth time in 10 games despite the return of captain Shane Doan.
Mike Smith finished with 23 saves.