Williams driver Pastor Maldonado has set the fastest time in the first practice session ahead of the European Grand Prix in Valencia.
The 27-year-old, who won the Spanish Grand Prix last month, topped the time sheet with Red Bulls' Sebastian Vettel and Mark Webber setting the second and third quickest pace respectively.
McLaren driver Jenson Button, who has claimed just two points in the last four races, recorded the fourth fastest time, while his teammate Lewis Hamilton, who was successful at the Canadian Grand Prix a fortnight ago, came in at eighth.
The second practice session will commence at 1pm UK time.