World Championship leader Lewis Hamilton topped the timesheets on the first day of testing at Monza.

Ten teams were in action on a day when the air temperature hit 31 degrees, and with the humidity making conditions almost unbearable, even for locals.

That said, following predictions of rain showers today, and heavier downpours forecast for tomorrow, there were a few spots of rain mid afternoon, before a heavier shower in the closing half hour of the session.

Following suggestions from the Grand Prix Drivers' Association (GPDA) the second chicane, scene of numerous incidents over the years, including a multi car crash a few years back which resulted in the death of a marshal, has had the gravel removed and the run off area covered in asphalt (above and below). According to sources at the track there no plans for any further modifications until after next week's Grand Prix.

Hamilton was on duty for McLaren as the Woking team started to work through a preparatory programme for next week's Italian Grand Prix.

The test focused on the low downforce configuration that will be used for the race on the legendary high speed circuit, alongside various aerodynamic upgrades. Some tyre evaluation also took place, with the track traditionally tough on durability.

The Englishman's programme during the morning session was temporarily interrupted with a CV joint failure, however he returned to the track soon after.

Kimi Raikkonen was on duty for Ferrari, the Finn concentrating on defining the set-up for the F2007 and on development of aerodynamic solutions aimed specifically at this track.