Singapore Grand Prix: Car problems for Lewis Hamilton in practice in yet another setback

Rosberg has moved to within two points of Mercedes team-mate Hamilton

Lewis Hamilton takes a moment to himself after a disappointing day (Getty)

Lewis Hamilton's championship assault hit another road bump on Friday after he was forced out of practice for the Singapore Grand Prix with a mechanical problem.

Nico Rosberg, who has moved to within two points of Mercedes team-mate Hamilton's title lead by virtue of winning both of Formula One's races following its summer break, set the fastest time under the lights at the Marina Bay Street Circuit.

But Hamilton, 31, was only seventh, and more than one second adrift of his championship rival when the issue - which Mercedes confirmed as a hydraulic problem - saw the Briton watch the final 30 minutes of the second session from the back of the team's garage.

It marked a troubled day for Hamilton, who is bidding to bounce back from his slow start which gift-wrapped victory to Rosberg at Monza's Italian Grand Prix a fortnight ago, and with it threw the championship back open.

Rosberg, who crashed out of first practice after making an error at turn 18 and sustaining damage to his front wing, returned later in the evening to post a lap of one minute and 44.152 seconds to finish the day fastest ahead of the Ferrari of Kimi Raikkonen and Red Bull's Max Verstappen, who had been quickest in the opening session.

While it was not a straightforward day for a Mercedes team which has dominated the sport for the best part of three seasons, they will be relieved to be back on top, 12 months after they were mysteriously off the pace here.

Nevertheless the opposition appear to be much closer to them than at any point of the campaign so far. Raikkonen finished only 0.275 seconds adrift of Rosberg's best time, while Verstappen was within four tenths with his Red Bull team-mate Daniel Ricciardo close behind. Sebastian Vettel, in the sister Ferrari, was fifth.

McLaren driver Jenson Button claimed on Thursday that he was targeting a respectable seventh place on Sunday, but the 2009 world champion, who will not be racing in Formula One next season after recently announcing he will take a break from the sport, could manage only 12th.

Nico Rosberg is celebrating his 200th Grand Prix start in Singapore this weekend (Getty)

The early phase of his opening session was also blighted by a mechanical problem within his McLaren which saw him stop on track after completing just one lap. He was pushed back to the pit lane after some impressive work from the marshals.

Jolyon Palmer, the 25-year-old Briton who is desperately trying to convince his Renault bosses he is worthy of a second season in the sport, finished 17th, marginally slower than his team-mate Kevin Magnussen.

Elsewhere, Chase Carey - the sport's new chairman following Liberty Media's £6.4billion purchase from CVC Capital Partners last week - appeared in the paddock for the first time.

American Chase, flanked by the sport's chief executive Bernie Ecclestone, said: "At this point I am asking questions, and not providing answers."