The Ganassi driver stayed out a lap longer than then-leader Will Power to take the advantage during the final round of stops, but was passed by Dragon Racing’s Sebastien Bourdais on a restart with 16 laps remaining.

There was some dispute over whether Bourdais moved early, although it was reviewed and declared clean by race control.

Although Bourdais was ahead, the combination of fading red tyres and the fact that he was out of push-to-pass left him vulnerable to Dixon, and the New Zealander picked him off a short time later.

With a clear track, Dixon opened a gap of 3.3 seconds, only to lose it when Alex Tagliani spun while trying to pass Simon Pagenaud and brought out the yellows again.

The restart came with a lap to go, this time with the field organised in single-file, and Dixon nailed it to secure the win.

Bourdais held on to finish second in a dramatic turnaround for Dragon Racing after the team’s poor start to the season, while early race leader Dario Franchitti survived a late lunge from Power to cross the line in third.

But even as the Scot was celebrating on the podium, word came from race control that he had been issued a time penalty for blocking Power on the final lap, dropping him to 13th and promoting Marco Andretti to third.

The encounter with Franchitti didn’t work out well for Power either, who had lunged into a miniscule gap between the Scot and the wall, bounced off the Ganassi car, and went nose-first into the Turn 3 barrier.

In a blink, he plummeted from fourth to 15th.

Typically for Toronto there were a number of incidents but few drivers had more things go wrong than reigning champion Ryan Hunter-Reay, who stalled in both of his stops, and then hit the wall while battling Andretti team-mate EJ Viso.

The race was scheduled to feature the first-ever standing start in an IndyCar-sanctioned race, but that was abandoned when Josef Newgarden stalled on the grid.

Under the regulations, the race was switched to a rolling start.