FORMULA ONE: Lewis Hamilton upbeat despite car problem cutting short Singapore practice

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 an indifferent day for Hamilton, who is bidding to bounce back from the slow start which gift-wrapped victory to Rosberg at Monza’s Italian Grand Prix a fortnight ago.

“They have fixed the valve and it is changed now, so it should be no problem tomorrow,” an upbeat Hamilton said.

“We are in a good position to go for pole position. Obviously Nico got a lot more running in, but hopefully it should not be a problem for us.

“These things happen. I feel optimistic and good at this track. It is a street circuit and these are the ones I generally go really well on, so I am looking forward to tomorrow.”

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 best 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.

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. His Red Bull team-mate Daniel Ricciardo was 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 could manage only 12th. 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 on Friday.

American Chase was flanked by F1’s chief executive Bernie Ecclestone, whose personal future in the sport appears uncertain.

Mercedes boss Toto Wolff has been mentioned among the possible candidates to replace Ecclestone, but Niki Lauda, the team’s non-executive chairman, believes it is unlikely that his fellow Austrian will leave the champions.

“We are busy with our work here at Mercedes, and we have contracts so there is no interest at all,” Lauda said on Friday night.