SPA-FRANCORCHAMPS, Belgium, Aug 31 AFP – Kamui Kobayashi topped the times for Sauber during Friday morning’s rain-drenched opening Formula One practice session for Sunday’s Belgian Grand Prix.

The 25-year-old from Japan was one of a handful of drivers to complete more than ten full laps as most teams elected not to spend much time on track due to the amount of rain falling on the Spa Francorchamps circuit.

Kobayashi went fastest with half an hour remaining before improving on his time nine minutes before the end of the session, clocking a lap of the historic circuit in one minute 11.389 seconds.

Venezuelan Pastor Maldonado of Williams was just 0.5 seconds slower in second followed by Toro Rosso drivers Australian Daniel Ricciardo and Frenchman Jean-Eric Vergne who were third and fourth-quickest respectively.

Red Bull driver Australian Mark Webber, fifth quickest, was the fastest of the title contenders followed by Mexican Sergio Perez in the second Sauber.

German Nico Rosberg of Mercedes was seventh fastest followed by Finn Valtteri Bottas in the other Williams.

German Michael Schumacher, who celebrates his 300th Grand Prix this weekend was ninth fastest in the other Mercedes followed by his compatriot Sebastian Vettel who completed the top ten in the second Red Bull.