McLaren, Ferrari and Sauber opted to remain in Italy to conduct their pre-Indianapolis testing, and joined forces at Mugello on the first of a three-day session.

Unsurprisingly, given his testing pace all summer, Olivier Panis topped the times for McLaren as the Woking team sought a set-up with which to regain the initiative at the USGP. The BAR-bound Frenchman clocked 1min 25.96secs in the course of a session-high 86 laps, and wound up over a second quicker than his fastest rival after an untroubled day.

Against expectation, however, it was not Ferrari's Luca Badoer who pushed Panis the hardest, but Sauber's Pedro Diniz. More remarkably, the Brazilian conducted his test carrying an injury sustained at Monza on the weekend, and which is likely to force him out of his second day's running today [Wednesday]

''My right hand proved very painful today,'' Diniz recounted, ''I strained the muscles during the accident at the start of the Italian GP, and it has since swollen too much to allow me to drive any more.''

The Brazilian's case was made worse by the fact that Sauber's physio, Josef Leberer, had had to return home following the unexpected death of his mother, leaving no-one to treat the injury. Diniz claims that he will be fir to race at Indianapolis, however.

The Swiss team also took the opportunity to give Formula Renault stand-out Kimi Raikkonen his first run in an F1 car, as it seeks to move to the head of the queue of teams keeping tabs on the young Finn. Despite fears from within that the 20-year old Manor Motorsport protege may not be ready for the potential of the C19, Raikkonen kept the car on the road, and will be rewarded with a second day's running today.

''I was afraid that he might bring the car back in pieces,'' admitted test team boss Jacky Eeckelaert, ''but he has made no mistakes and, on the same rubber, was only 1.5secs slower than Pedro, in spite of his lack of F1 experience. On Wednesday, we will continue his training, while assessing his sensitivity to changes in the car's set-up.''

Sauber's programme focused on general set-up work with one eye on Indianapolis, but as Eeckelaert admitted, anything more than estimates were difficult to make.

''Obviously, it is not possible to do specific preparation work for the new Indianapolis track, but we do know that it will require low to medium downforce,'' he revealed, ''We are focusing on general preparation, with the added bonus of being able to try the hard and extra hard compound tyres that Bridgestone will supply in America.''

Despite his injury, Diniz completed 78 laps of the Tuscan circuit, lapping half a second quicker than Badoer in the Ferrari. The Italian's session was spoiled by an accident part way through and, although Ferrari requested that the day be extended to allow them to make up for lost time, he could not find enough time to edge closer to Panis.

Testing continues for all three teams today, before being suspended on Thursday as a mark of respect to the marshal killed at Monza on the weekend. Paolo Ghislimberti's funeral will be attended by colleagues working at Mugello, as well as a delegation from Ferrari.

Leading performances (12 September):

Olivier Panis McLaren-Mercedes 1min 25.96secs 86 laps
Pedro Diniz Sauber-Petronas 1min 27.66 secs 78 laps
Luca Badoer Ferrari-Ferrari 1min 28.14secs 65 laps
Kimi Raikkonen Sauber-Petronas 1min 30.01secs 29 laps

[Times courtesy of Red Bull Sauber Petronas]