The Leafs improved to 2-1-0 in the preseason while the Flyers fell to 1-0-1.
An enthusiastic crowd at London's John Labatt Centre was on hand to see local favorite Nazem Kadri, who is expected to crack the Maple Leafs' lineup this season.
Kadri, the Leafs' top draft choice a year ago, played on a line with Armstrong and Versteeg. He didn't get much room during the game from the tight-checking Flyers, but he did score the Leafs' first goal in the shootout.
After a defensive first period in which Bourdon scored the only goal, the game opened up a little in the second period with both teams getting decent chances.
Versteeg made a nice play breaking in from the right wing when killing a penalty and forcing Flyers goalie Brian Boucher to make a good save.
The Leafs pressed hard during a power play and were rewarded when McKegg scored shortly after the Flyers returned to full strength. But the cheering hadn't stopped when Guerin put the Flyers ahead again with an unassisted goal.