Lewis Hamilton is back on top of the Formula One standings for the first time in 18 months after a stunning Canadian Grand Prix win.

Back-to-back victories for the McLaren star means he now holds a three-point cushion over team-mate Jenson Button as the Woking marque finished one-two for the second consecutive race.

Hamilton held the lead on three separate occasions around the Circuit Gilles Villeneuve before finally taking it for good on lap 50, going onto to clinch his second triumph here in three attempts.

As expected, there were incidents at the start, with Sauber's Pedro de la Rosa skidding across the first-corner grass and the Silverstone-built Force India of Vitantonio Liuzzi and Ferrari's Felipe Massa colliding after starting fifth and sixth.

Then there was the second Sauber of Kamui Kobayashi attempting a pass, losing his front wing and clipping a wall, but there was no safety car. So it became a question of how long Hamilton and Button could stay out on the soft tyres Red Bull team principal Christian Horner had described earlier this week as "crumbling like cheese."

The answer was only a handful of laps as Button pitted first, then Hamilton, with old foe Fernando Alonso directly behind him, culminating in the duo sparking their rivalry again as they exited the pit lane.

The double world champion just had the edge on the Briton, the duo going wheel to wheel as they made their way back onto the circuit, with the latter ultimately having to yield.

Momentarily, the Toro Rosso of Sebastien Buemi held the lead for the first time in his career, but a failed attempt at a pass from Alonso at the hairpin soon allowed Hamilton to reclaim the lead.

Mark Webber slowly started to edge away from Hamilton, opening up a gap of 12 seconds at one point, but as his second set of hard tyres dropped off, so the Briton reeled him back in. On lap 50 Hamilton made his move, reclaiming the lead again - and for good - before Webber finally made his second stop to switch to the softs at the end of it.

Six laps later Alonso made his second mistake as he found himself held up by Hispania's Karun Chandhok, allowing Button to dive up the inside and so seal the team one-two.

Alonso claimed third, with Sebastian Vettel fourth and Webber fifth, the trio now 15, 19 and six points behind Hamilton respectively.

Mercedes' Nico Rosberg was sixth, followed by Kubica, Buemi and the Force India duo of Vitantonio Liuzzi and Adrian Sutil, who dropped the woeful Michael Schumacher to 11th on the final lap. The seven-times champion is also under investigation for a late clash with Ferrari's Felipe Massa that forced the Brazilian into a fourth stop for a new front wing.