Lewis Hamilton was fastest in the first session of free practice today for this weekend's Malaysian Grand Prix.

The 2008 world champion had climbed to the top of the timesheet midway through the session on the Sepang circuit and his time of one minute 34.921 seconds had looked good enough to put him on top of McLaren one-two ahead of Jenson Button.

However, Mercedes' Nico Rosberg clocked 1:35.106secs on his last lap to leap above Button and into second place.

Rosberg's team-mate Michael Schumacher recovered from a slow start to go fourth fastest.

The seven-time world champion was the only driver still to set a timed lap with less than 30 minutes of the session remaining as his team made adjustments to his car but he was soon on the pace when he was on the track.

Renault's Robert Kubica maintained his recent good form with the fifth fastest lap with Red Bull's Mark Webber sixth and Force India's Adrian Sutil seventh.

Championship leader Fernando Alonso was eighth fastest for Ferrari while Sebastian Vettel could only manage ninth after enduring a couple of issues with his Red Bull. Toro Rosso's Sebastien Buemi rounded out the top 10.

Force India reserve driver Paul di Resta once again took to the circuit for a practice session after debuting in Australia and the the Scot was 15th fastest while Lotus test driver Fairuz Fauzy made his first appearance at a grand prix weekend.

The Malaysian finished within half a second of his team-mate Jarno Trulli and took 22nd place.