Rielly took a pass from Auston Matthews on a 2-on-1 and shot glove side for the win.
Matthew Knies and Oliver Ekman-Larsson scored and Dennis Hildeby made 30 saves for the Maple Leafs (26-13-2), who have won four in a row and five of their past six.
Tyson Foerster and Scott Laughton scored and Ivan Fedotov made 22 saves for the Flyers (17-18-5).
The Flyers went up 1-0 at 3:24 of the first period when Foerster shot past Hildeby’s blocker from the top of the right face-off circle.
Knies tied it 1-1 at 4:02, scoring his fourth goal in the past two games, when he put in a rebound over a sprawling Fedotov.
Ekman-Larsson put the Maple Leafs up 2-1 at 18:52. He poked a loose puck past Fedotov after he made a left toe save on Steven Lorentz and kicked the rebound out into the slot.
Laughton evened it 2-2 at 11:08 of the second period when he took a cross-ice pass from Sean Couturier and put a shot between Hildeby’s pads at the side of the net.
Maple Leafs defenseman Jake McCabe left the game and did not return after sustaining an upper-body injury in a fight with Garnet Hathaway at 19:54 of the first period.
