Fernando Alonso assumed the top spot following the second day of Formula 1 testing at Monza as McLaren continued to dominate proceedings.

Alonso only had the chance to test in the afternoon after Lewis Hamilton, who had been quickest on the first day of testing, spent the morning driving the sole MP4-22, scoring a best lap of 1min 23.454 in 49 laps.

Despite a brief shower during lunch, the circuit dried enough after the break to allow Alonso to just undercut his team-mate's time with a lap of 1min 23.155secs in the same amount of laps.

The team, as with many others, concentrated on aerodynamic and tyre developments on the Bridgestone Potenza tyre, with both Alonso and Hamilton a fair way up on the rest of their competition, which was led by Nick Heidfeld in the BMW.

The German continued to work on setting up the F1.07 ahead of next weekend's race at the Italian circuit and, like the McLaren's, worked on establishing a good feel with the Bridgestone tyres. Completing 81 laps with a best lap of 1min 23.725secs, Heidfeld will hand over to 2006 podium sitter Robert Kubica for the final day of testing, whether that be Thursday or Friday depending on the weather.

Jarno Trulli and Toyota were an encouraging fourth fastest, the Italian running Heidfeld close having spent the day fettling the TF107's aerodynamics.

"We had a good day and improved many aspects of the car," he said. "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 at Monza in next week's Italian Grand Prix. The home fans are always assionate and enthusiastic and I have seen that again these past two days. I hope that I can give them something to cheer!"

Kimi Raikkonen meanwhile continued to work on the set-up for the upcoming race, but slipped from the second place he occupied on the first day to finish the second in fifth position having completed a relatively meagre 59 laps. He hands over to Turkish Grand Prix winner Felipe Massa for the final day.

Heikki Kovalainen took over from Nelson Piquet Jr. in the sole Renault, hauling his car up to sixth fastest, even though it was reverted back to running to 2007 specifications after the team tried out a 2008 ECU on the car yesterday. Kovalainen was pleased with his day's work.

"We had a good day, and the car got better with every run. We worked hard so that by the end of the day, the R27 was well-balanced. I think this will be a good baseline to work from on Friday at the Grand Prix, and at that time, we will focus on fine-tuning the setup to extract the final tenths of a second for the race. The team did a good job today, and we made encouraging progress."

Sebastian Vettel, who goes to Monza looking for a better result that he managed in Hungary and Turkey, was again amongst the leading positions in seventh having managed the largest number of laps at 101. The German continued to get some much needed additional miles under his belt having been forced to adapt quickly when he made the step up from World Series to Formula 1. He will however, as many drivers, hand over to his team-mate tomorrow, in this case Vitantonio Liuzzi.

Alex Wurz was given the Williams for the second day of testing having been in the hands of test driver Kazuki Nakajima on the first day, although he suffered a small technical gremlin in the afternoon.

"Alex joined us today and we completed the majority of our planned programme with him, despite having a couple of showers today and a small technical problem in the afternoon," said test team manager Dickie Stanford. "Nico joins us for tomorrow's running, although with 80-85% humidity today, we are anticipating some wet weather tomorrow which may not allow us to complete our full programme."

Christian Klien assumed duties for Honda as he desperately attempts to extract speed out of the RA107 ahead of the Italian Grand Prix, although while he was just ninth quickest, the Austrian was less than a second behind Heidfeld in third.

Mark Webber stayed in the Red Bull car for the second day in a row, also working on aerodynamic and tyre development. His time was enough to place him tenth, ahead of the Super Aguri of Takuma Sato.

Finally, Adrian Sutil ensured all eleven teams would feature on the timesheets as Spyker joined proceedings with the long awaited B-specification of their F8-VII.

Although the car, which has now passed the FIA crash test, was slowest, the German was just three tenths behind Sato having spent the day getting familiar with a car that had not been track tested before today. It was enough to give the German encouragement ahead of its race debut.

"Today was in general quite good. We planned to do some more running but we had a small issue in the afternoon with the gearbox and lost a little time, but otherwise a good day.

"We worked on finding a good set-up for the race and understanding how the car behaves in low downforce configuration and also tried out the soft and harder tyres, which seemed to work well for us. It is difficult to say where we are with the new car; Monza is a very special track unlike anywhere else with less grip, but I think it was a good start."

Testing is due to continue tomorrow (Thursday), although the forecast for wet conditions means it could well be put back to Friday to ensure the final test of the season gets completed with more valuable dry running.

Testing times (29 August) - Monza:

1. Fernando Alonso McLaren-Mercedes 1min 23.155secs49 laps
2. Lewis Hamilton McLaren-Mercedes 1min 23.454secs49 laps
3. Nick Heidfeld BMW Sauber 1min 23.725secs 84 laps
4. Jarno Trulli Toyota-Toyota 1min 23.759secs 61 laps
5. Kimi Raikkonen Ferrari-Ferrari 1min 23.773secs 59 laps
6. Heikki Kovalainen Renault-Renault 1min 24.093secs 51 laps
7. Sebastian Vettel Toro Rosso-Ferrari 1min 24.266secs 101 laps
8. Alex Wurz Williams-Toyota 1min 24.356secs 70 laps
9. Christian Klien Honda-Honda 1min 24.595secs 92 laps
10. Mark Webber Red Bull-Renault 1min 24.701secs 83 laps
11. Takuma Sato Super Aguri-Honda 1min 24.976secs 80 laps
12. Adrian Sutil Spyker-Ferrari 1min 25.278secs 76 laps

all times unofficial - courtesy McLaren

Track/weather conditions: Hot and humid, with a shower midway through the day: Track temperature, 32.1?C / Ambient temperature, 26 ?C.

Comparative lap times:

Italian GP 2006:

Pole position: Kimi Raikkonen McLaren-Mercedes 1min 21.484secsFastest lap: Kimi Raikkonen McLaren-Mercedes 1min 22.559secs