As is the case in the Friday free-practice sessions, the twenty regular race drivers are augmented by the 'third drivers' of BAR, Minardi, Jaguar, Jordan and Toyota.

As previously reported, having sorted out his "personal difficulties", Giorgio Pantano is back in his race seat this week, while Timo Glock, who scored two points in his race debut in Canada, returns to the job of 'third driver'

Air temperature is 28 degrees, while the track temperature is a staggering 45 degrees, and it's not quite eleven-o-clock.

When the lights go green, signalling the start of the session, Zsolt Baumgartner is first out, followed by Glock, Klien, Pantano, Bruni, da Matta, Davidson, Wirdheim, Fisichella and Panis.

With just three minutes of the session gone, everyone has been out, everyone that is except the Ferraris and BARs. A few moments later Michael drives out of his garage, followed, shortly afterwards, by his faithful teammate.

Eight minutes into the session, Toyota's Ricardo Zonta comes out for his second run, as does Timo Glock.

The Brazilian posts the first time of the weekend, 1:14.468, which is about 3.2s off last year's pole time. As Glock posts 17.909, Zonta keeps chipping away, gradually improving his time.

Wirdheim goes second with a 1:15.391, as Anthony Davidson goes straight to the top of the timesheets with a 1:13.472, the Englishman clearly having re-found his pace following his Montreal crash. Meanwhile, BAR teammates Button and Sato come out for their installation lap.

Davidson improves to 1:13.431, as Leinders goes fourth, behind Zonta and Wirdheim, and Baumgartner goes sixth. Moments later, Pantano posts 1:15.260, to go third.

Twenty-three minutes into the session, Michael Schumacher is the first of the 'big guns' to come out. The German immediately goes quickest in the first two sectors, crossing the line at 1:11.619, that's 1.812s quicker than Davidson.

As the World Champion begins another fast lap, Felipe Massa goes third, the Brazilian clearly recovered from his Montreal crash.

Michael goes quickest in sector one as Ralf goes second with a 1:13.293, that's 1.674s slower than his brother. Elsewhere Klien goes fifth and Heidfeld seventh.

Juan Pablo Montoya goes second with a 1:12.669, as Barrichello comes out to post his first time of the day. Jenson Button is also back on track.

Rubens goes quickest with a 1:11.593, as Button goes third, 0.960s off the Ferrari driver's time.

At the halfway stage the order is: Barrichello, Michael, Button, Montoya, Ralf, Davidson, Massa, Zonta, da Matta and Klien. Fisichella, Panis, Alonso, Trulli, Raikkonen, Webber, Coulthard and Sato have yet to post a time. Moments later Coulthard posts 1:13.916, to go seventh.

Sato goes seventh only to be forced down the timesheets by Alonso who goes sixth with a 1:12.989, and Panis who goes fourth with a 1:12.631.

Continuing his recent good form, and clearly with an eye on job vacancies at Grove, or wherever, Giancarlo Fisichella goes fourth with a 1:12.575. The two Ferraris are around 0.9s quicker than the rest.

Another bad session for Minardi, as Gianmaria Bruni spins in the second sector and fails to keep the engine going. His session is over. The session is stopped while marshals remove the Italian's stricken car.

After forty-two minutes, Bjorn Wirdheim has completed the most laps (17), but remains thirteenth quickest. Still no times for Raikkonen or Webber.

Rubens still quickest, ahead of Michael, Button, Fisichella, Panis, Montoya, Alonso, Ralf, Zonta and Trulli. Davidson is eleventh, ahead of Sato, Wirdheim, Coulthard, Massa, da Matta, Klien, Heidfeld, Pantano and Glock.

After a couple of minutes the car is removed and the session is restarted.

AS the lights go green, Michael, Rubens and Button are first out, followed by Panis and Montoya.

Davidson goes quickest in the fist sector, but loses a little ground in the second. At the line it's 1:11.693, the Englishman goes third, just 0.100s off Barrichello's pace.

However, the Brazilian hits back by going quickest in the first sector, however he too loses ground in the second sector. Next time around the Brazilian improves to 1:11.516 as teammate Schumacher goes quickest in the final sector, though the German fails to improve. Barrichello raises the benchmark, posting a 1:11.354, as Webber finally comes out, as does Raikkonen.