The 1973 Canadian Grand Prix, run on this day at Mosport's scenic and undulating track, was anything but a clear cut affair.
From the outset, rain threw a spanner in the works of a race marked by tyre changes, chaotic circumstances, a Safety Car - a first at the time for F1 - and countless lead changes that put the final result in jeopardy for several hours.
Howden Ganley, Emerson Fittipaldi and Peter Revson were all penciled in as winners at one point by the officials or by their respective teams.
Eventually however, after the officials triple-checked their lap charts, McLaren's Revson was declared the final victor, the American claiming on the day his second Grand Prix triumph of the year.
