It was a McLaren clean sweep at Monza today, when Fernando alonso topped the timesheets ahead of Lewis Hamilton. The Englishman had driven in the morning before handing over testing duties to his Spanish teammate, both drivers completing 49 laps.

Although there were a couple of rain showers during the afternoon, the predicted heavy downpour never arrived. Although much of the session took place under overcast skies, it remained warm at the Italian track, though thankfully, the humidity which had made conditions almost unbearable on Tuesday had subsided.

In the morning, Hamilton continued the programme of preparation for next week's Italian Grand Prix. Aero work was accompanied by further tyre comparisons over a couple of long runs.

As the test team changed the settings of the car for Alonso over lunch, there was a light rain shower, however the track had dried before the Spaniard took to the track at 14:00. On one of his first runs, the World Champion's car ground to a halt just yards outside the McLaren garage, causing panic among the Woking crew who were quick to form a protective wall around the stricken car. Though the assembled team members, with the help of security screens, were able to keep the photographers at bay, there were unable to shield the Spaniard from the jeering that emanated from the grandstand opposite... after all, this is Ferrari country.

Running until 17:00, Alonso carried on with the aerodynamic testing, whilst also spending some time focused on set-up and mechanical work.

Third quickest was Nick Heidfeld, as BMW continues to make impressive progress. The German continued working on the set-up of the car, concentrating mainly on mechanical adaptations. He also did a comparison of the two tyre compounds which will be used for the Italian Grand Prix.

Jarno Trulli continued for Toyota, the Italian focussing on developing the team's low downforce Monza aerodynamic package. Ralf Schumacher takes over driving duties tomorrow.

"We had a good day and improved many aspects of the car," said the Italian. "I was much happier with the braking stability and we also made strong progress with the aerodynamic set-up. We improved our lap time, which is positive, and I am now confident of a strong race here next week.

"The home fans are always passionate and enthusiastic," he added, "and I have seen that again these past two days. I hope that I can give them something to cheer!"

"Monza is a one-off in terms of car set-up," admitted test team manager, Gerd Pfeiffer, "but we made significant progress today, with both the aerodynamics and the brakes, which was satisfying.

"Jarno felt much more comfortable in the car and that is an important consideration at what is the fastest track on the Formula 1 calendar. Tomorrow we will start afresh with Ralf in the cockpit and, weather permitting, will complete our schedule of work."

Kimi Raikkonen continued with the programme begun on Tuesday, comprising finding the best set- up for the F2007 on this circuit and on development of new aerodynamic and mechanical solutions for the forthcoming race. Felipe Massa takes over from the Finn on Thursday.

After completing the first day of this week's test running a car fitted with the 2008-specification standard ECU, Renault's first full track test with this new component, the French team reverted to a more traditional programme for day two.