Ferrari's Fernando Alonso splashed his way to the top of the timing screens Friday in a rain-soaked free practice for the Belgian Grand Prix. The double world champion, chasing his team's fourth successive Spa success, was quickest in the morning and afternoon sessions at the longest track on the calendar. The Spaniard set the best time of the day, a lap of one minute 49.032 seconds, at the end of an interrupted second session on a drying track after heavy cloudbursts in the morning. The session was halted for 12 of the last 15 minutes, frustratingly just as there was the chance of some dry running, after reports that spectators had strayed into dangerous positions around the circuit. Alonso's late lap ousted Force India's Adrian Sutil from the top at a track where the German's team took its first pole position, podium and points last year with Italian Giancarlo Fisichella. McLaren's Lewis Hamilton was second and third fastest respectively with Robert Kubica making good use of the new ‘F-duct' on his Renault to lay down the third and fourth best times. Red Bull's championship leader Mark Webber, presented before the session with a cake topped with a chocolate racing car on his 34th birthday, was only seventh in the morning, with German teammate Sebastian Vettel fourth. The Australian, four points clear of Hamilton at the top of the standings with seven races remaining, fell to 18th after lunch. Vettel is third in the championship, 10 points off Webber. Alonso is a further 10 points back. Brazilian Rubens Barrichello, marking his 300th race this weekend, was ninth quickest in both sessions despite spending much of the morning in the garage as Williams changed his car's steering rack. McLaren's world champion, Jenson Button, fourth in the championship with 14 points to make up on Webber, was sixth and seventh fastest in the two sessions.