He captured the race on the streets of the Ontario capital despite a problem with his left-rear tire during his first stop.
Later, the Chip Ganassi Racing driver would benefit when Graham Rahal was involved in an incident just when Franchitti entered pit road before a caution flag.
"I guess we timed it right with strategy," Franchitti, the 2007 series champion, said following his third victory this season and 11th in his IndyCar career.
Team Penske's Ryan Briscoe was second and Briscoe's teammate, Will Power, was
third. Scott Dixon finished fourth and last weekend's winner at Watkins Glen, Justin Wilson, beat out Danica Patrick for fifth place.
Copyright 2009 by United Press International.