Roloson was tested often in the meeting of two division leaders but withstood four Flyers' power plays and came away with his fourth shutout of the season and the 28th of his 13-year career.
Purcell scored 19 seconds into the game on a 2-on-1 rush with Vincent Lecavalier and added his second tally only a minute later on a deflection in the Lightning's sixth straight win.
Steve Downie and Steven Stamkos also tallied for the Bolts.
The Flyers pulled Sergei Bobrovsky from the nets following the first period after he allowed three goals on six shots and Brian Boucher entered, turning aside 15-of-16 shots the rest the way.
Philadelphia, co-leader of the NHL with 71 points, dropped its third straight against the Southeast Division-leading Lightning.