Mercedes pair Nico Rosberg and Lewis Hamilton dominated the track in the first and second practice sessions at the Malaysian Grand Prix on Friday.
Rosberg topped the timesheet in the opening session of the day as he edged ahead of his teammate by nearly half a second.
Hamilton failed to better his teammate following a lock-up on Turn Nine, but the talking point from the session was Kevin Magnussen's Renault catching fire.
As a result, the practice was delayed, but the problem persisted for Magnussen as while in the pits, fuel leaked and reignited the fire.
Ferrari pair Sebastian Vettel and Kimi Raikkonen were the closest to challenging the times of Mercedes, while McLaren's Fernando Alonso clocked the fifth-fastest lap, with Red Bull just behind.
In the second session, Hamilton rose to the top of the timesheet as his best lap was 0.223 seconds quicker than Rosberg, while Vettel and Raikkonen were third and fourth respectively.
Max Verstappen of Red Bull recorded the fifth-quickest time, just ahead of Force India's Sergio Perez and Alonso.
Rosberg currently leads the driver rankings by eight points.