Briton Davidson clocked 1:45.104, three-tenths of a second quicker than Ferrari's championship leader Michael Schumacher as Formula One returned to the Spa-Francorchamps circuit after a one-year absence having being omitted from last year's calendar because of a ban on tobacco advertising.

Germany's Schumacher, who will wrap up a seventh world title if he wins for the 13th time in 14 races this season on Sunday, was 0.197 seconds ahead of Ferrari team mate Brazilian Rubens Barrichello.

Jaguar's third driver Bjorn Wirdheim, of Sweden, set the fourth best time in the hour-long session, but was more than 1.5 seconds adrift of Davidson in a time of 1:46.658.

His Jaguar team mates Australian Mark Webber and Austrian Christian Klien completed a positive start to the weekend for the British-based team as they finished seventh and eighth fastest respectively.

McLaren's Kimi Raikkonen was the fifth quickest with Renault's Fernando Alonso sixth.

Italian Giorgio Pantano was involved in the only incident when he braked late into the La Source hairpin and stalled his Jordan before pushing it from the track himself. He ended the first session 20th.