Mercedes’ Nico Rosberg remained at the top of the times during the second practice session for the Bahrain Grand Prix.
Rosberg was fastest on the Soft tyres early on before he improved on the Super Soft compound, posting a lap of 1:31.001 in the night session at Sakhir.
Lewis Hamilton completed a Mercedes 1-2, 0.241s behind his team-mate, while Jenson Button was a surprise third for McLaren, albeit over a second adrift of his compatriot.
Max Verstappen demonstrated Toro Rosso’s pace with the fourth best time, ahead of Ferrari pair Kimi Räikkönen and Sebastian Vettel.
Vettel’s time came on the Soft tyre after he made a couple of mistakes on his Super Soft run and failed to improve.
It proved to be a difficult session for Vettel as he stopped on track with 15 minutes remaining, citing a loose rear left wheel on his SF-16H.
Red Bull and Williams rounded out the top 10, with Daniil Kvyat heading Valtteri Bottas, Daniel Ricciardo and Felipe Massa, the latter duo separated by just 0.003s.
Stoffel Vandoorne was 11th fastest, 0.7s behind team-mate Button, as he fills in for Fernando Alonso, who was ruled out by FIA doctors due to rib fractures sustained in Australia.
Haas was firmly midfield with Esteban Gutiérrez and Romain Grosjean in 12th and 14th, sandwiching Carlos Sainz Jr.’s Toro Rosso.
It wasn’t all plain sailing for Haas though as Grosjean lost part of his front wing during the second session, littering debris onto the circuit at Turn 13.
Force India and Renault filled the next four positions, with Sergio Pérez leading the quartet despite sitting out the opening session in favour of Alfonso Celis Jr.
Kevin Magnussen, Nico Hülkenberg and Jolyon Palmer all trailed marginally behind Pérez, while Manor's Pascal Wehrlein finished ahead of both Sauber drivers.
Marcus Ericsson could manage only 20th, three-tenths adrift of the German rookie, with Felipe Nasr in 21st position, as Sauber’s struggles continued.
Rio Haryanto was the slowest of the 22 drivers, placing a tenth of a second behind Nasr and 3.5s adrift of pace setter Rosberg.