Ahead of the fourth, and final, free practice session for the Canadian GP, the ambient temperature remains at 16 degrees C, while the track temperature has risen to 19 degrees.

Mark Webber is first out, the Jaguars have had a difficult weekend thus far. The Australian completes his installation lap and then continues around, as teammate Christian Klien comes out to join him.

Webber posts a 1:16.529 to set the benchmark, though it's likely we'll be looking at a best time in the mid-1:13s by the end of the session.

Glock comes out, as does da Matta, Fisichella, Baumgartner, Heidfeld, Trulli and Raikkonen.

Klien goes quickest, the Austrian posting 1:15.176, as Glock posts 1:17.561.

David Coulthard goes quickest in the second sector and again in the third, crossing the line at 1:14.766. Moments later Alonso slips in behind the Scot, having posted 1:14.812. Button however, leapfrogs the pair of them, the BAR driver crossing the line at 1:14.675.

Alonso goes quickest with a 1:14.427 while Button also improves but remains second, elsewhere Michael can only manage twelfth, despite having been quickest in the second sector. Next time around the German posts 1:13.581, the quickest lap of the weekend, and 0.846s quicker than Alonso.

Trulli goes fifth, behind Coulthard, as Schumacher improves to 1:13.420. Raikkonen goes sixth ahead of Ralf. Meanwhile Montoya goes eleventh, 1.96s off the pace, in what looks likely to be another disappointing race weekend for the Grove outfit.

Schumacher is quickest, ahead of Alonso, Button, Coulthard, Trulli, Raikkonen, Ralf, Montoya, Klien and Fisichella. No times from either Barrichello nor Sato, both of whom have failed to appear, thus far.

Fernando Alonso goes quickest in the first sector, then again in the second. The Spaniard crosses the line at a staggering 1:12.901, as Jarno Trulli goes even quicker in the first sector. The Italian crosses the line at 1:12.833, an unbelievable time, even Michael Schumacher looks impressed, and rightly so.

The two Renaults now top the timesheets, ahead of Michael, Raikkonen, Button, Coulthard, Ralf, Montoya, Klien and Fisichella.

Twenty-seven minutes into the session and Barrichello and Sato finally appear. The Brazilian goes twelfth with a 1:15.619, while the Japanese driver goes sixth with a 1:14.190. Moment later Rubens improves to fifth. Elsewhere Webber improves to ninth.

Button improves his time, but remains ninth, 0.3s off his teammate's pace.

At the bottom of the timesheets it's almost perfect symmetry, with the Minardis propping up the Jordans and Toyotas. While the WilliamsF1s in eleventh and twelfth are both over 2s off the pace.

At the top of the timesheets, it's the Renaults ahead of Schumacher and the two McLarens.

With eight minutes remaining, Schumacher, Raikkonen, Barrichello, and Webber are all on track, as are Glock and Bruni. Everyone else remains in their respective garages, watching.. waiting.

Barrichello goes quickest in the second sector, though he loses ground in the second. He crosses the line at 1:13.904, an improvement, but he remains seventh.

Next it's Button's turn to go quickest in the second sector, unlike the Brazilian he maintains his pace, subsequently crossing the line at 1:13.026, to go third, ahead of Schumacher.

As da Matta improves to ninth, Sato goes fourth with a 1:13.235. Meanwhile Trulli goes quickest of all in sector one. The Italian improves to 1:12.629 as Montoya goes fifth, meanwhile Alonso goes quickest in the first sector. Sadly, the Spaniard loses ground over the reminder of the lap and fails to improve.

Trulli heads back to the pits, confident that he's got the perfect set-up for qualifying, and indeed the race. Alonso also heads back to base, the session ends.

Jarno Trulli tops the timesheets ahead of teammate Fernando Alonso, with Jenson Button third ahead of Sato, Montoya, Michael, Raikkonen, Coulthard, Barrichello and Klien.

da Matta finishes the session eleventh ahead of Ralf, Webber, Fisichella, Panis, Massa, Heidfeld, Glock, Baumgartner and Bruni.