Although Monza was spared the thunderstorm that hit the circuit towards the end of first practice on Friday, the conditions were still treacherous.

Early in the session, on ordinary wet tyres and when the track did not have large pools of standing water in places, Toyota's Timo Glock set the fastest time of one minute 35.464 seconds.

To underline the situation, that was 10 seconds slower than Kimi Raikkonen's best lap in his Ferrari in dry conditions on Friday afternoon.

The session concluded with the remarkable sight of Lewis Hamilton at the bottom of the timesheets, with a lap of 1:46,325, almost 11 seconds down on Glock.

However, the current championship leader did his running in his McLaren towards the end when the rain was at its heaviest and on extreme wet tyres.

In between top and bottom, Toro Rosso's Sebastian Vettel was second overall, with Nico Rosberg in his Williams third, to complete an all-German top three.

With times virtually irrelevant given the conditions, Jarno Trulli was over a second down in fourth in his Toyota, followed by the Williams of Kazuki Nakajima and BMW Sauber's Nick Heidfeld.

Behind David Coulthard in seventh for Red Bull came Felipe Massa in his Ferrari, with Fernando Alonso ninth for Renault and Giancarlo Fisichella 10th for Force India, nearly two seconds down.

Just above Hamilton at the bottom were Raikkonen 18th and McLaren team-mate Heikki Kovalainen in 19th.