Lewis Hamilton completed his dominance of practice on Friday by topping the timesheet in the afternoon session ahead of this weekend's Malaysian Grand Prix.

The 2008 world champion was fastest in the morning session on the Sepang circuit ahead of Brackley-based Mercedes GP Petronas team driver Nico Rosberg, and again set the pace in the afternoon with a time of one minute 34.175 seconds.

Hamilton clocked that time midway through the session to boost his confidence ahead of Saturday's qualifying following a frustrating race in Australia last weekend.

Sebastian Vettel set the second fastest lap of 1:34.441secs after initially complaining of a problem with the power steering in his Red Bull.

There were reliability woes for Vettel's team-mate Mark Webber, though, as the Australian was forced to park his car in the gravel with less than 30 minutes of the session gone due to suspected engine failure.

Rosberg set the third fastest time, while reigning world champion Jenson Button was fourth.

Seven-time world champion Michael Schumacher once again failed to get the better of Mercedes team-mate Rosberg as he took fifth.

Australian GP runner-up Robert Kubica was sixth in his Enstone-built Renault, while championship leader Fernando Alonso improved one place from the first session to go seventh fastest for Ferrari.

Toro Rosso's Sebastien Buemi, Vitaly Petrov of Renault and the Silverstone-built Force India of Adrian Sutil rounded out the top ten.