Alonso leads first practice - Canada

The world champion was two tenths of a second quicker than teammate Lewis Hamilton, while the Ferraris were within four tenths of Alonso time as they took third and fourth.

With the little-used track extremely dusty, only a handful of drivers ventured out in the first third of the session, with the Toyotas leading the times at first.

They were usurped by the Ferraris after 50 minutes, as Kimi Raikkonen moved to the top with a 1:18.136 on his second lap, 0.031 seconds ahead of Felipe Massa's first effort. Hamilton then deposed them with a 1:18.005 shortly afterwards.

When Alonso emerged, he commenced a long stint that began with a string of ever-quicker laptimes, as he closed in on his teammate's benchmark and ultimately surpassed it with a 1:17.559 on his seventh lap.

Hamilton improved on his second run, but only found a tenth and would remain second, while a potentially better lap by Alonso was spoilt by a sideways moment at the final chicane.

Mark Webber vaulted to fifth for Red Bull with his last lap of the session, ahead of Giancarlo Fisichella.

Nick Heidfeld took seventh but his teammate Robert Kubica failed to set a time - the BMW mechanics having to use fire extinguishers on the rear of the Pole's car when he returned to the pits after aborting his first run.

Despite taking to the Turn 8 grass on his final lap, Ralf Schumacher ended up eighth for Toyota, ahead of David Coulthard, who also had several brief trips off the road.

Last minute improvements by Anthony Davidson and Takuma Sato brought the Super Aguris up to 10th and 11th, with Jarno Trulli completed the top 12.

For the first time since Sepang, there was a test driver amongst the Friday practice field. With no clashing GP2 commitment this time, Kazuki Nakajima returned to action for Williams, replacing Nico Rosberg for the morning and setting the 17th fastest time on his first experience of the Montreal track.

Pos  Driver        Team                    Time               Laps
 1.  Alonso        McLaren-Mercedes   (B)  1:17.759            17
 2.  Hamilton      McLaren-Mercedes   (B)  1:17.967  + 0.208   20
 3.  Raikkonen     Ferrari            (B)  1:18.136  + 0.377   21
 4.  Massa         Ferrari            (B)  1:18.167  + 0.408   21
 5.  Webber        Red Bull-Renault   (B)  1:18.301  + 0.542   21
 6.  Fisichella    Renault            (B)  1:18.620  + 0.861   24
 7.  Heidfeld      BMW Sauber         (B)  1:18.634  + 0.875   20
 8.  R.Schumacher  Toyota             (B)  1:18.652  + 0.893   32
 9.  Coulthard     Red Bull-Renault   (B)  1:18.717  + 0.958   24
10.  Davidson      Super Aguri-Honda  (B)  1:18.896  + 1.137   16
11.  Sato          Super Aguri-Honda  (B)  1:18.898  + 1.139   20
12.  Trulli        Toyota             (B)  1:18.925  + 1.166   25
13.  Button        Honda              (B)  1:18.932  + 1.173   24
14.  Kovalainen    Renault            (B)  1:18.997  + 1.238   26
15.  Wurz          Williams-Toyota    (B)  1:19.189  + 1.430   22
16.  Speed         Toro Rosso-Ferrari (B)  1:19.234  + 1.475   29
17.  Nakajima      Williams-Toyota    (B)  1:19.273  + 1.514   30
18.  Barrichello   Honda              (B)  1:19.937  + 2.178   18
19.  Liuzzi        Toro Rosso-Ferrari (B)  1:20.331  + 2.572   12
20.  Albers        Spyker-Ferrari     (B)  1:21.251  + 3.492   17
21.  Sutil         Spyker-Ferrari     (B)  1:21.630  + 3.871   25
22.  Kubica        BMW Sauber         (B)  No time              2