Ferrari ended final practice for the Singapore Grand Prix 1-2 after Sebastian Vettel dominated proceedings as light faded at Marina Bay.
Vettel was quickest on the Prime compound and retained an advantage of almost half a second when drivers switched to the Option tyres.
Vettel’s lap of 1:45.682 was 0.45s clear of team-mate Kimi Raikkonen, while Red Bull emerged as its nearest challenger.
Daniil Kvyat was third, with team-mate Daniel Ricciardo in fourth position.
That left Mercedes in a lowly fifth and sixth place, with Lewis Hamilton ahead of Nico Rosberg, despite a scruffy session, over a second behind Vettel.
Fernando Alonso was only 0.014s behind Rosberg in seventh position, with Toro Rosso collecting eighth and ninth courtesy of Carlos Sainz Jr. and Max Verstappen.
Marcus Ericsson completed the top 10 for Sauber, ahead of Valtteri Bottas, Nico Hulkenberg, Jenson Button and Felipe Massa.
Lotus’ difficult weekend continued as Pastor Maldonado and Romain Grosjean could muster only 15th and 17th, split by Sergio Perez.
Felipe Nasr claimed 18th spot, leaving Alexander Rossi and Will Stevens to round out the table.