Romain Grosjean made the perfect start to the weekend where he can seal the GP2 championship by topping free practice at Spa on Friday.
The DAMS driver moved to the top of the times 12 minutes into the session, when the track was predominantly dry. Rain started to fall four minutes later, preventing anyone else from being able to beat his time.
Grosjean's lap could have been even quicker, as he lost time at the Bus Stop chicane while putting a surprisingly bold pass on Luca Filippi under braking. The Italian did not appear too happy with the late lunge, and he went wheel to wheel with the championship leader down the start finish straight in retaliation.
Filippi's Coloni teammate Michael Herck jumped up to second just before the rain hit, while Marcus Ericsson (iSport) set the third quickest time ahead of Grosjean's closest title rival Giedo van der Garde.
The Addax driver had a spin on the entry to Fagnes while the track was at its best, as he caught a damp curb while turning in. Later in the session he was one of the first to venture out on wet weather tires, meaning he looked at ease with the conditions as others tentatively joined him a few minutes later.
At around the same time, ART's Jules Bianchi headed out of the pits on slick tires. He returned at the end of his out-lap, but it was an experiment worth taking given that Spa has already been hit by three heavy showers this morning.
While a few other drivers had spins as the rain intensified, the only casualty of the session was Jolyon Palmer. The Arden driver spun shortly after the pit exit, pitching him into the wall on the right-hand side.