Revisit the Canadian Grand Prix through the eyes of social media, as Sebastian Vettel maintained his lead to the chequered flag. (1:00)

Brendon Hartley has been given the all-clear by doctors after his scary crash at the start of the Canadian Grand Prix.

The Toro Rosso driver was squeezed into the wall by the wobbling Williams of Lance Stroll on the opening lap, sending Hartley's car sideways and launching him into the air briefly. The incident knocked both drivers out of the race and prompted a brief period under the Safety Car.

After both drivers visited the medical centre, Hartley was sent to a nearby hospital for precautionary tests. He completed two electrocardiogram tests, which came back with normal results, before returning to the circuit by helicopter.

Stroll appeared to lose control of his car as he came through the kink leading towards Turn 6, at which point Hartley was between his car and the wall. The Canadian driver felt it was a racing incident -- an assessment the race stewards agreed with by declining to penalise either driver after a brief investigation during the race.

"I had a good start and I gained a few positions," Stroll said."I was side-by-side with Brendon going into Turn 5, the car got loose on me and I corrected it, but there was not much room for both of us.

"By the time I corrected it, we touched and went into the wall."