Click here for full FP1 results for the Canadian Grand Prix
Lewis Hamilton has demonstrated his dominance at Circuit Gilles Villeneuve by being the early pacesetter with a lap less than half a second off his 2015 pole position time, while the session was temporarily halted after Felipe Massa crashed.
With the lap times largely off the mark as the 'green' circuit was cleaned up by the F1 cars Ferrari's Kimi Raikkonen became the initial leader, before the session was suspended by Massa's off into the barriers at turn one.
The Williams driver appeared to lose grip from his rear tyres under heavy braking as the DRS flag shut, leaving the Brazilian helpless in sliding off track and into the wall.
After a 13-minute delay to clear Massa's stricken Williams, FP1 restarted with a little over 50 minutes remaining to signal the start of the competitive times.
With almost all drivers finding the maximum levels of grip, as plenty of cars drifted on to the run-off heading into the final chicane, Hamilton dialled in his Mercedes to break into 1m 14s before quickly improving his best to a 1m 14.755s – less than half a second off his 2015 pole time.
F1 championship leader Nico Rosberg backed up the Mercedes advantage in Canada by taking second with a 1m 15.086s ahead Sebastian Vettel in the Ferrari with its new turbo.
Looking to bounce back from his Monaco crash Max Verstappen split the Ferraris in fourth ahead of Raikkonen with Valtteri Bottas acting as 'best of the rest' – over half a second off Raikkonen.
Sainz in the Toro Rosso split the Force Indias in eighth with Nico Hulkenberg seventh and Sergio Perez narrowly ahead of McLaren's Fernando Alonso.
Daniel Ricciardo struggled to find outright hot lap pace with his Red Bull down in 11th in front of Jenson Button who missed large chunks of the session with an oil temperature issue on his Honda-powered McLaren.
Romain Grosjean nipped ahead of the stricken Massa with Daniil Kvyat ahead of the second Haas of Esteban Gutierrez.
The Manor of Rio Haryanto lead the back-markers after both Saubers and Renault's Kevin Magnussen suffering technical issues, as Jolyon Palmer completed the 22 cars.