Sergei Bobrovsky stopped 24-of-27 shots in the win.
"He made some big saves tonight and stood on his head a couple of times," Hartnell said about Bobrovsky. "We needed it, he needed it and we have to keep rolling."
The lone goal of the first period belonged to the Flyers with 5:22 left in the frame when Erik Gustafsson's shot from the left point was stopped in a crowd in front of the net, but Hartnell batted the bouncing puck past Reimer and then immediately dropped the gloves with Toronto's Dion Phaneuf, who laid a big hit on Hartnell behind the net moments before the goal.
Toronto then knotted the game at one just 54 seconds into the second period when Bozak received a pass in the right circle and swooped around behind the net before throwing a shot on net from the left circle that deflected in off the skate of Philadelphia's Braydon Coburn.
Philadelphia took the lead back less than three minutes later on Talbot's deflection of an Andrej Meszaros wrister from the point, but the Leafs answered with Lupul's power play goal at the 5:57 mark of the frame when he cleaned up Phaneuf's slap shot from the right point that Bobrovsky couldn't corral with his glove.
A quick wrister from Giroux from the right circle that snuck under the crossbar at the 13:53 mark of the middle stanza and a one-timer from the left of the net from Schenn off a big rebound 1:14 later put the Flyers up 4-2.
But Bozak finished off an offensive flurry in front of Bobrovsky by elevating the puck over the prone goaltender with 1:51 remaining to make it a 4-3 game after two.
"We didn't really start playing until the beginning of the second period. They had us on our heels," Toronto head coach Ron Wilson said. "We looked like we didn't want the puck in the first period and once we kind of took a deep breath and realized they weren't doing anything different then we expected, we put our nose to the grindstone and fought our way back into the game."
The Leafs, though, could not get another puck past Bobrovsky in the third, including while on a 6-on-4 advantage in the final two minutes after pulling Reimer in the midst of a power play.
The Flyers improved to 13-8-5 at home this season, while the Leafs fell to 12-13-2 on the road this season...Toronto's Phil Kessel had his three-game goal streak snapped...Philadelphia went 0-for-4 on the power play. Toronto has now gone 17 straight games without allowing a power-play goal...The Leafs were 1-for-4 on the man advantage.