Simon Pagenaud kept his IndyCar title hopes alive by edging reigning series champion Scott Dixon in Toronto. Alexander Rossi completed the podium for Andretti Autosport Honda as he narrowed title-rival Josef Newgarden's championship advantage.
Pagenaud managed to hold the lead off the line, allowing the Frenchman to fully utilise his qualifying advantage. However, it was less of a positive start for his Penske teammate Will Power.
The Australian who was aiming to improve from his lacklustre qualifying displays attempted a move on Graham Rahal - only for it to end in chaos as Matheus Leist, Marcus Ericsson, Ryan Hunter-Reay and Marco Andretti were all caught in the crossfire of the action.
Upon the return of green flag racing Ed Jones acted swiftly, moving up to fourth in the process for Ed Carpenter Racing, ahead of Alexander Rossi.
The championship then took a critical turn in the first round of pitstops as Alexander Rossi managed to hold off perennial title rival Josef Newgarden in the stops.
Rossi also managed to repass the #20 Ed Carpenter Racing machine of Ed Jones to further boost his title tilt.
Ed Carpenter Racing's strong weekend was then turned upside down as teammates Jones and Spencer Pigot collided, leaving them both out of contention.
As the race began to reach its climax at the front as Dixon stalked Pagenaud. The reigning series champion was then aided by his former Chip Ganassi Racing teammate Tony Kanaan.
As the AJ Foyt racing car was held up the race-leading Penske to bring Dixon ever closer.
Rahal Letterman-Lanigan's weekend then hit rock bottom as Takuma Sato was forced to retire from the race with an engine failure.
Will Power's dreadful weekend was then ended as he hit the wall in his Penske, compounding a miserable showing.
Meanwhile, back at the front Dixon hounded Pagenaud as more pressure was mounted with the aide of traffic, but nothing was stopping Pagenaud claim a Toronto win.
Newgarden also had late drama as he tapped the wall on the final lap; curtailing his late charge to relieve Rossi of a podium spot.
Behind the top four, Felix Rosenqvist produced a solid drive for Chip Ganassi to secure another top five and the badge of top rookie in Toronto.
Behind him was home-favourite James Hinchcliffe, while Colton Herta recovered from a below-par qualifying to finish seventh.
Eighth was the lead Dale Coyne Racing car of Sebastien Bourdais, just ahead of Graham Rahal and Marco Andretti, both of whom managed to secure top ten results despite their first lap contact.