Lewis Hamilton held onto his position at the top of the timesheets during final practice for the Canadian Grand Prix, despite failing to improve when he bolted on super-soft tyres at the end of the session.
Once again he had the edge over Mercedes team-mate Nico Rosberg, who was also beaten by Felipe Massa's Williams, which took second place under 0.5s off Hamilton. However, Mercedes appeared to be holding something back as both drivers failed to go quicker on the super-soft tyres at the end of the session when the track conditions were at their best.
Massa's quick lap was set on his second attempt on the super-softs, suggesting the rubber is taking a couple of laps to get up to its optimum operating temperature. Fernando Alonso was fourth fastest, over 0.7s off Hamilton and just 0.016s quicker than Daniel Ricciardo, who appears to have made a recovery from his disappointing Friday pace.
Kimi Raikkonen was the first driver to switch to super-softs and ended up with the sixth fastest time, nearly a full second off the pace of Hamilton at the front. Valtteri Bottas was seventh fastest, 0.6s shy of Williams team-mate Massa, who will be hoping to be closer to when it matters in qualifying.
The Toro Rossos again showed impressive pace, with Daniil Kvyat eighth and Jean-Eric Vergne ninth, proving the Renault engine, even when not in a Red Bull, can compete in the top ten on a power-based circuit. Sebastian Vettel completed just 15 laps over the hour as his mechanics spent much of the end of the session working on the front end of his car.
Force India and McLaren both found themselves outside the top ten despite having the power advantage of the Mercedes engine, with Sergio Perez and Kevin Magnussen both spinning during the session while Jenson Button complained of a vibration early in the session. The two Lotuses of Romain Grosjean and Pastor Maldonado were in the mix with the two Mercedes-powered teams, but their lack of straight-line speed is still proving costly ahead of qualifying.
Sauber again look set to bridge the gap between the midfield and the backmarkers, but Esteban Gutierrez did not help matters when he spun off 15 minutes into the session. He lost the rear on the exit of Turn 3 and then failed to catch the slide as he went sideways through Turn 4 and clouted the barrier with his left-rear wheel. Sauber will have two hours to assess the damage, with the possibility of the knock to the rear resulting in a gearbox change ahead of qualifying.