Lewis Hamilton clung on to the fastest time of opening free practice at the Canadian Grand Prix by just over a tenth of a second as the season's race winners queued up behind him.
The Briton, who claimed his maiden F1 victory at the Circuit Gilles Villeneuve in 2007 and has always had an affinity for the venue, took several stops in P1 during the interrupted 90-minute session, but moved back to the head of the pack with 20 minutes to go, and then withstood a last-ditch effort to dislodge him from Sebastian Vettel.
The reigning world champion twice improved his time on his final run, first moving into third spot at the expense of Fernando Alonso, and then shaving another tenth to vault above Nico Rosberg into second spot. Vettel had appeared to be on course to claim P1 too, but lost a little time in the final sector and remained 0.118secs behind Hamilton's pace-setting 1m 15.564secs effort.
Rosberg was exactly a tenth slower than his countryman, with Alonso just six-hundredths off the Mercedes, with Mark Webber rounding out the top five, 0.333secs off Hamilton, and Nico Hulkenberg giving Force India early encouragement by becoming the sixth driver to break the 1min 16secs barrier. Sauber's Kamui Kobayashi could not have come any closer to joining the sextet either, recording 1min 16.000secs on his best run.
Sauber enjoyed a strong session, with Sergio Perez backing up his team-mate in eighth spot, while Michael Schumacher and Jenson Button rounding out the top ten. The Briton, however, was forced to sit out much of the second half of the session after a grip problem was found to be an oil leak that led to clutch slip on his McLaren.
Paul di Resta came close to joining team-mate Hulkenberg in the top ten, but his 1min 16.460secs effort put him ahead of Felipe Massa and Spanish GP winner Pastor Maldonado, with Lotus pairing Romain Grosjean and Kimi Raikkonen - both early pacesetters - having to settle for 14th and 15th in the final reckoning.
While a number of drivers joined Button in having technical niggles, and others - such as Vettel and the Ferraris - took part with their cars sporting either flo-vis paint or unsightly data-logging add-ons, the biggest incident of the session came with 40 minutes remaining as Heikki Kovalainen caught the turn nine wall and removed the right-hand side from his Caterham.
After the engine failure that brought-out the red flag in FP1 in Monaco, it was another blow for the Finn, who appeared to lose the right-rear corner on what was a slightly moist circuit, before its contact with the wall tipped the right-front into the concrete. The clear-up took fully 20 minutes, while Kovalainen's wait for his car to be repaired will be significantly longer.
Despite his misdemeanour, the Finn did enough in his 16 laps to finish 19th overall, just behind Caterham team-mate Vitaly Petrov, but ahead of the second Williams of Bruno Senna which, after having its right-front wheel clipped by Vettel, also trailed the best of the HRTs, in the hands of Pedro de la Rosa.
If the Montreal crowd turned out to welcome the F1 circus, so too did the local wildlife, with assorted foxes, squirrels and groundhogs all taking turns to cross the circuit during the 90 minutes. Fatalities, this time around at least, were zero.