Nico Rosberg claimed a comfortable P1 in the opening practice session at Sepang as his only true rival, Lewis Hamilton, was out with engine troubles.
As Rosberg stormed to the top of the timesheets, Hamilton's morning ended after just four laps when he heard a "click" from the back of his W06.
The Brit was told by his Mercedes pit wall to park it and he did just that, his session over.
Hamilton, though, did tell his team that he could bring the car back to the pits but, given that drivers have just four engines for the entire season, Mercedes felt it would be better for him to stop.
Mercedes later confirmed it was an engine issue. The team tweeted: "Crew currently investigating an engine problem for Lewis Hamilton – not the ideal way to start but we're working hard to analyse."
With Hamilton out of the session, Rosberg had it all his own way to finish up with a 1:40.124.
That put him 0.373s up on Kimi Raikkonen while Sebastian Vettel was third, 0.861s down. Both drivers put in their best times at the very end of the session.
Vettel, though, only ventured out in the latter half of FP1 as Ferrari noted his car's temperatures were not as they should be after his installation lap so they opted – as a precaution – to change one of the radiators.
Romain Grosjean, who topped the speed trap, was fourth quickest ahead of Carls Sainz, Daniel Ricciardo and Max Verstappen.
However, once again Ricciardo and his team-mate Daniil Kvyat were not happy with their cars. While Ricciardo complained that "traction is weak", Kvyat said "something strange is going on with brake and power."
Valtteri Bottas was eighth quickest on his return, one of two who had to be cleared to race by the FIA's medical delegate. The other was Fernando Alonso.
Taking part in his first session with McLaren since the 2007 Brazilian GP, the Spaniard finished P14, 2.761s off the pace, while his team-mate Jenson Button was 17th, a further 0.2s back.
Meanwhile Manor put in their first laps of the season with Will Stevens covering eight laps with a best time of 1:46.686. His team-mate Roberto Merhi also managed eight and was a second slower.
1 Nico Rosberg Mercedes 1:40.124 20 laps
2 Kimi Raikkonen Ferrari 1:40.497 0.373 17 laps
3 Sebastian Vettel Ferrari 1:40.985 0.861 13 laps
4 Romain Grosjean Lotus 1:41.543 1.419 14 laps
5 Carlos Sainz Toro Rosso 1:41.596 1.472 26 laps
6 Daniel Ricciardo Red Bull 1:41.787 1.663 15 laps
7 Max Verstappen Toro Rosso 1:41.803 1.679 23 laps
8 Valtteri Bottas Williams 1:41.882 1.758 23 laps
9 Daniil Kvyat Red Bull 1:42.055 1.931 18 laps
10 Marcus Ericsson Sauber 1:42.064 1.940 16 laps
11 Felipe Massa Williams 1:42.103 1.979 23 laps
12 Pastor Maldonado Lotus 1:42.567 2.443 19 laps
13 Raffaele Marciello Sauber 1:42.621 2.497 13 laps
14 Fernando Alonso McLaren 1:42.885 2.761 20 laps
15 Nico Hulkenberg Force India 1:42.893 2.769 13 laps
16 Sergio Perez Force India 1:43.054 2.930 15 laps
17 Jenson Button McLaren 1:43.100 2.976 19 laps
18 Will Stevens Manor 1:46.686 6.562 8 laps
19 Roberto Merhi Manor 1:47.683 7.559 8 laps
20 Lewis Hamilton Mercedes No time 4 laps