Nico Rosberg ended the first day of Malaysian Grand Prix practice fastest for Mercedes, continuing his strong run of form at the start of the 2014 Formula 1 season.
The Australian Grand Prix winner was among the first of the frontrunners to switch onto the faster medium-compound tyre.
He knocked Felipe Massa’s Williams, which had been the first to top the timesheets on the quicker rubber, off top spot shortly after the 30-minute mark.
Rosberg’s Mercedes team-mate Lewis Hamilton went second fastest, a tenth-and-a-half slower than Rosberg, shortly afterwards but appeared to have the pace to go quicker but for a slow middle sector.
The Mercedes were then split by the back-on-form Kimi Raikkonen, who was only 0.035s slower than Rosberg as he went second for Ferrari.
This was just enough to retain second ahead of Sebastian Vettel, whose Red Bull set its fastest time on his second flying lap on medium rubber, which suggests the RB10 is proving to be kind on its tyres in the heat of Malaysia.
Fernando Alonso ended up fifth fastest, half a tenth slower than Hamilton and just eight thousandths of a second quicker than Massa.