The reigning world champion clocked a 1m15.988s on the super-soft tyres, 0.316 seconds clear of Ferrari’s Sebastian Vettel at Montreal’s Circuit Gilles Villeneuve. The session looked set to be a washout when predicted rain fell with 50 minutes remaining, but Mercedes decided to send Hamilton and team-mate Nico Rosberg out on intermediates.
It proved to be a mistake as Hamilton aquaplaned on the approach to the hairpin and was powerless when his Mercedes slid into the tyre wall, damaging the front end of the car. Hamilton had already survived two scary moments during the session at Montreal’s infamous final chicane in the dry, first avoiding Romain Grosjean and later bouncing across the kerbs on an aborted quick lap.
Following heavy rain, Mercedes then made an ill-advised decision to send its drivers out on intermediate tyres on a track that had been soaked in an attempt to gather start data.
After he literally sailed into the tyrewall, Hamilton simply reported: “aquaplaned”.
The session was red-flagged while marshals recovered the damaged Mercedes, which swung back into the tractor as it was pulled out of the wall, and there was no further running.
It compounded a scrappy day for Hamilton, who also spun at the hairpin during the first session and clobbered the kerbs at the final chicane in second practice before completing a tidier lap to set the pace. With rain always predicted, teams wasted little time sending their drivers out on track at the start of the session to make the most of the dry conditions, particularly as it is expected to dry on Sunday.
Vettel was straight out on the super-softs and went quickest with a 1m16.304s before Hamilton put a clean lap together to top the times, finishing 0.452s clear of team-mate and title rival Nico Rosberg back in fourth.
Kimi Raikkonen was third quickest with Ferrari splitting its programme and swapping the Finn to the softs while leaving Vettel on the super-softs to maximise data gathering.
Lotus’s Pastor Maldonado was an impressive fifth, ahead of Williams’s Valtteri Bottas and the other Lotus of Romain Grosjean. Williams driver Felipe Massa was eighth with Red Bull’s Daniil Kvyat and Daniel Ricciardo completing the top 10.
Nico Hulkenberg finished 11th for Force India, the German having to pit with a left-rear puncture, which Pirelli suggested was related to the rim rather than the tyre itself, 10 minutes into the session. Sauber’s Marcus Ericsson was 12th, ahead of the Toro Rosso of Carlos Sainz and Force India’s Sergio Perez.
Fernando Alonso was the leading McLaren in 15th with Toro Rosso’s Max Verstappen, who will take a five-place grid penalty following his collision with Grosjean in Monaco, 16th.