A fired-up Sebastian Vettel has his sights set on laying his recent demons to rest after posting the fastest time in practice ahead of Sunday's Canadian Grand Prix.

Perhaps with a point to prove this weekend at the Circuit Gilles Villeneuve, Vettel was one of only two drivers to dip under 77 seconds for the 4.361km track on the Ile Notre Dame in the middle of the St Lawrence Seaway.

The 22-year-old German, who trails championship leader Webber by 15 points, sizzled in the cool Montreal air by posting a lap of one minute 16.877secs.

Although Ferrari have been woefully off the pace of late, Fernando Alonso was a very close second, finishing just 0.086secs adrift of Vettel, with the two in a class of their own.

Nico Rosberg underlined the continuing improvement of the Brackley-based Mercedes team with third ahead of Webber, who finished almost four tenths of a second behind Vettel, and the second Ferrari of Felipe Massa, with Silverstone's Force India team's Adrian Sutil sixth.

After claiming third and first in the earlier 90-minute session, the McLaren duo of Lewis Hamilton and Jenson Button were down in seventh and 11th respectively, the latter a second down.

The McLarens are expected to perform well here, but even allowing for discrepancies in fuel loads in practice, their times were surprising.

In between the two most recent world champions were Enstone's Renault F1 team driver Robert Kubica in eighth, with the Pole describing the greasy, slippery surface as the worst he has driven on in his time in F1.

Michael Schumacher followed in his Mercedes in ninth - after the 41-year-old seven-times champion was second quickest in the morning - with Vitantonio Liuzzi for Force India in tenth.

The final six positions were taken up by the three new teams, with Virgin Racing duo Timo Glock and Lucas di Grassi bringing up the rear, the latter 4.7secs off the pace.

Heikki Kovalainen at least offered Lotus Racing a degree of hope as he was only three seconds down in 19th, just 0.7secs behind the Toro Rosso of Jaime Alguersuari.