Felipe Massa proved to be the man to beat as a wet track kept many of the top drivers in their garages for the better part of Friday's opening practice session in Canada.
The session began with the track still damp from early morning showers and with the meteorologists predicting further rainfall during the hour and a half.
Nick Heidfeld was the first driver to hit the track and within ten minutes of practice starting all the drivers barring Jenson Button and the two Ferraris had completed their installation laps.
Adrian Sutil put in the first lap time of the day, a 1:33.637, only to lose out to Giancarlo Fisichella who clocked a 1:29.166 on his third timed lap.
The Force India duo lost out to Kazuki Nakajima who went fastest with a 1:28.574. He shaved over a second off his time while his team-mate Nico Rosberg slotted into second place. Rosberg, however, was deposed by Sebastian Vettel only to fight back a lap later and take the top spot on the timesheets.
Halfway through the session a dry line had begun to form, however, there were still damp patches around causing problems for some of the drivers as did the slippery conditions.
Heidfeld was the next driver to take the P1 slot, posting a 1:26.441. His reign was short-lived as Timo Glock took over only to lose out to Trulli in a Toyota 1-2.
However, seconds later Trulli found himself facing the wrong way as he spun his Toyota at Turn Six after losing the rear end under acceleration out of the corner. The Italian was able to continue.
Felipe Massa crept his way into the top three, improving to second place on the next lap, trimming three tenths off his time. The Ferrari driver dropped a position when Vettel hit the front, clocking a 1:25.711.
65 minutes into the session Glock became the first driver to gamble on the dry weather tyres, easily going quickest by four seconds ahead of Vettel. Trulli improved to second place.
With ten minutes on the clock Fernando Alonso and Kimi Raikkonen finally completed their first timed laps of the day. Alonso went P4 while Raikkonen was 11th quickest, 5.4s off the pace. The Finn, however, improved his time on the very next lap, taking the P1 slot by 0.651s.
Seconds later he was dethroned by Rosberg only to fight back and return to the top of the timesheets with a 1:19.914. Mark Webber went third with Massa P4 ahead of Glock. Raikkonen further slashed the benchmark time to a 1:18.292 while Lewis Hamilton finally arrived out on track for his first timed lap of the morning. The Brit, though, could only manage P18 on his first lap, 4.1s off the pace.
Hamilton improved to third place, slotting in behind Massa who moments before had taken P2. The duo joined Raikkonen in the 1:18s.
Conditions remained slippery with Jenson Button outbraking himself at the chicane at Turns Eight and Nine. The Brit had to take to the grass before moments later Massa had a similar off-track excursion.
Hamilton crossed the line to clock second quickest in 1:18.314, just fractions behind Raikkonen while Kubica slotted into third place. All three drivers though were dropped as Massa went fastest.
Trulli suffered his second spin of the morning, this time at the Casino hairpin, as the chequered flag came down on the session.
Kubica, Heikki Kovalainen and Heidfeld all improved after the session was completed, however, none were able to beat Massa's 1:17.553.
Times
01 F. Massa Ferrari 1:17.553 14 laps
02 R. Kubica BMW 1:17.809 12 laps
03 H. Kovalainen McLaren 1:18.133 10 laps
04 N. Heidfeld BMW 1:18.182 13 laps
05 K. Räikkönen Ferrari 1:18.292 12 laps
06 L. Hamilton McLaren 1:18.303 8 laps
07 M. Webber Red Bull 1:18.712 11 laps
08 D. Coulthard Red Bull 1:18.809 12 laps
09 K. Nakajima Williams 1:18.971 24 laps
10 F. Alonso Renault 1:19.005 13 laps
11 N. Rosberg Williams 1:19.093 20 laps
12 S. Vettel Scuderia Toro Rosso 1:19.228 21 laps
13 T. Glock Toyota 1:19.346 28 laps
14 J. Trulli Toyota 1:19.568 31 laps
15 G. Fisichella Force India F1 1:19.815 16 laps
16 A. Sutil Force India F1 1:19.888 15 laps
17 N. Piquet jr. Renault 1:20.091 23 laps
18 R. Barrichello Honda 1:20.173 17 laps
19 S. Bourdais Scuderia Toro Rosso 1:20.541 16 laps
20 J. Button Honda 1:21.542 17 laps
