Mark Webber set himself up for a memorable 35th birthday tomorrow when he topped the times for Red Bull in this afternoon's second free practice session for this weekend's Belgian Grand Prix.

The Australian, who is the only man among the leading drivers still without a win this year, clocked a fastest time of one minute and 50.321 seconds to outstrip his nearest rival Fernando Alonso of Ferrari by one-tenth of a second.

Two-times champion Spaniard Alonso was one of several men to trade fastest laps with Webber along with his Red Bull team-mate and defending champion German Sebastian Vettel and McLaren's Briton Jenson Button.

Seven-times champion German Michael Schumacher, 42, had topped the times in the morning's opening session for Mercedes, marking the 20th anniversary of his Formula One debut with a flourish.

But in the afternoon he wad down in 11th, five places behind his Mercedes team-mate compatriot Nico Rosberg, while Vettel wound up 10th.

Button was third ahead of his McLaren team-mate and fellow-Briton Lewis Hamilton, the 2009 and 2008 champions maintaining impressive progress on a day of near-incessant heavy rain at the majestic Spa-Francorchamps circuit in the sprawling pine forests of the Belgian Ardennes.

Alonso's Ferrari team-mate Brazilian Felipe Massa, a fortunate winner of last year's race, was fifth ahead of Rosberg, Mexican Sergio Perez of Sauber and German Nico Hulkenberg, who revelled in a rare opportunity to have a day's running for the Force India team.

Briton Paul Di Resta was ninth in the second Force India car ahead of Vettel and Schumacher.

Few fans at the track can have enjoyed their day other than the true die-hards as Spa's infamous and capricious micro-climate delivered a deluge that forced many to hide under canvas in the campsites.