McLaren's rookie Briton Lewis Hamilton topped the times in the third and final free practice session ahead of Sunday's Canadian Grand Prix.
Hamilton, who is racing at the Gilles Villeneuve circuit for the first time, showed the kind of pace that has seen him become the hottest property in Formula One.
Ferrari's flying Finn Kimi Raikkonen was second and Hamilton's teammate, double world driver's champion, Fernando Alonso was third.
In bright sunshine in Montreal many drivers again struggled for grip on the dusty track but it was Hamilton who dealt with the conditions best.
He seemed very relaxed and was laughing and joking with his engineers in the pitlane ahead of his first run.
The laid-back approach obviously served him well as he clocked a lap time of 1:16.071, nearly four-tenths of a second faster than Raikkonen's.
The hour-long practice session was reduced by 17 minutes after oil from Heikki Kovalainen's Renault engine got onto the track and the stewards were forced to wave a red flag and halt proceedings.
Smoke was billowing from the Finn's car and the slippery track conditions were deemed dangerous after Alonso nearly lost control of his McLaren.
The Ferraris showed early improvement from Friday's session with Raikkonen and his Brazilian teammate Felipe Massa, who was eventually fourth fastest, quickly clocking fast laps.
Once again though, McLaren indicated that they have a slight pace advantage over their Italian rivals.
Alonso was only able to complete nine laps but he was the only driver to move above Hamilton, albeit only momentarily.
The 22-year-old Hamilton, who is currently level on points with Alonso at the top of the championship, quickly reasserted himself and clocked a time that would not be bettered.