Singapore GP F1 practice: Rosberg fastest, problems for Hamilton

Rosberg clocked a 1m44.152s on the ultra-soft tyres to finish 0.245 seconds clear of Ferrari's Kimi Raikkonen with Red Bull's Max Verstappen a tenth further adrift in third.

Hamilton led the way in the early stages with a 1m45.275s on the super-softs, ahead of Daniel Ricciardo and Verstappen.

But he locked up heavily into Turn 1 on his qualifying simulation, skating into the run-off before rejoining and switching his focus to gathering long-run data.

The Briton, who ended up seventh, then pitted and climbed out of his car with just under half an hour to go.

Mercedes confirmed Hamilton's car had a "small hydraulic issue" and after investigating the problem, the team said it could not be resolved in time to get the car back together and called an end to his session.

Rosberg raised concerns over brake problems in the final few minutes, but continued until the end of the session.

Ricciardo spent a chunk of the session in the garage after he clipped the wall and spun at Turn 11 before rejoining and setting the quickest middle sector to finish fourth.

Sebastian Vettel ended up fifth, 1.009s off the pace and seven tenths slower than team-mate Kimi Raikkonen.

Force India's Nico Hulkenberg was sixth and nearly a second clear of his team-mate Sergio Perez in 11th.

Carlos Sainz Jr and Fernando Alonso both clipped the wall but continued to finish eighth and ninth respectively with Daniil Kvyat completing the top 10.

Williams had a low-key session, with Felipe Massa and Valtteri Bottas 14th and 15th respectively.

Romain Grosjean, who early in the session complained about the brakes being inconsistent, spun into the wall at the final corner, causing significant damage to his rear wing.

The Frenchman failed to complete a qualifying simulation and managed just 12 laps as he finished 19th.

PRACTICE TWO TIMES: