MONTREAL - McLaren's Lewis Hamilton returned to the scene of his first Formula One victory on Friday and put down an immediate marker with the quickest laps in Canadian Grand Prix practice.
The 2008 world champion, a winner in Montreal in 2007 and 2010 but strangely without a triumph in this most unpredictable of seasons, was fastest in both sessions at an overcast Circuit Gilles Villeneuve.
The Briton set a best time of one minute 15.564 seconds in the morning and improved on that slightly with a 1:15.259 in the afternoon session that concluded just before torrential rain and thunder swept across the city.
Hamilton is a strong favourite to become the seventh different winner in seven races on Sunday and also has his eyes on McLaren's 150th pole.
He said he could have gone faster.
"I was out there pushing for quite some time on the option tyre, it was very difficult to put all sectors together," Hamilton told reporters before the storm broke. "Sometimes I went a little bit quicker in one sector and then lost it in the second.
"I think qualifying looks like it could be very close...you've got the Ferraris who are very quick as well and their tyre degradation seems to be better. So I'm keeping an eye out for them."
The Briton was followed by the two Ferraris in the second session, championship leading Spaniard Fernando Alonso lapping 0.054 off Hamilton's pace and Brazilian Felipe Massa third best and 0.151 slower.
Red Bull's double world champion Sebastian Vettel, who was second fastest to Hamilton in the morning was fourth in the afternoon.
The German's Australian team mate Mark Webber, winner in Monaco for Red Bull, lapped fifth fastest in the morning but was well back in 12th in the second.
McLaren's Jenson Button, last year's winner after coming from the back of the field at the restart to pass Vettel on the final lap, completed only 12 laps due to an oil leak and was 10th on the timesheets.
He was able to improve on that effort later in the day with the ninth best time.
"Jenson can drive brilliantly here as we saw last year and we've just got to give him a decent chance to do that," said team principal Martin Whitmarsh.
Both sessions were delayed by crashes.
Bruno Senna brought out the red flag in the afternoon session when the Brazilian lost control of his Williams and slammed heavily into the 'Wall of Champions,' a notorious part of the circuit coming out a chicane entering the home straight that has claimed some of Formula One's best.
"I just pushed a bit too hard in the chicane," he said, after apologising to his mechanics. "This is the Wall of Champions for a good reason, everybody seems to have an issue with that wall.
"There's a lot of damage to the car but these guys (the mechanics) are going to get it sorted out and we are going to be back on track tomorrow."
Williams have brought a revised rear wing to Canada and Senna calmed fears that he might have to use an old type by saying he would have a spare one of the new specification.
The morning session was red-flagged for 13 minutes when Heikki Kovalainen hit the wall and wrecked his Caterham, spreading debris across the track.
"I was carrying a bit too much speed into that corner. I thought I'd got away with it but the rear end snapped away and that was it," the Finn told the BBC.