Canadian GP P3: Nico Rosberg quickest in red flag hit session

Nico Rosberg topped final practice ahead of the Canadian Grand Prix in a session disrupted twice by red flags.

But all was not well on the other side of the Mercedes garage as Lewis Hamilton completed just nine laps, propping up the timesheet in 20th.

After crashing out in Practice Two on Friday, Hamilton appeared to be suffering from problems under braking as the world champion was regularly seen locking up and taking to the run-off areas.

Felipe Nasr put his qualifying participation into doubt after hitting the wall in bizarre fashion. The Brazilian opened his DRS and then began weaving to get heat into his tyres and subsequently lost control, hitting the inside barrier and causing substantial damage to the front of the Sauber.

After a delay of around 10 minutes, the session resumed, but was soon stopped again when Jenson Button came to a halt with seven minutes remaining. Team boss Eric Boullier subsequently confirmed to Sky Sports F1 that the former world champion will require an engine change and will miss qualifying.

The sister McLaren of Fernando Alonso missed the majority of the session while his engine was changed, making it out on track for around four minutes before the Button red flag brought the session to an early conclusion.

In the Ferrari, Sebastian Vettel also had issues as he battled KERS problems and could only manage the eighth quickest time, finishing the session nearly a second slower than team-mate Kimi Raikkonen.

The standout performance of the session came from Romain Grosjean who set the third quickest time on the soft compound tyre, beating Valtteri Bottas and Sergio Perez on the supersofts.

The drivers once again found it difficult to get the tyres into the correct operating window, despite track temperatures hitting over 30c.

With it taking at least a couple of laps to generate enough heat in the Pirelli rubber, that is likely to become the crucial factor in this afternoon's fight for pole.

Qualifying is underway at 5pm UK time on Sky Sports F1, with the session itself starting at 6pm.