Red Bull's Sebastian Vettel signalled his title defence isn't over yet Friday as he scorched to the quickest times in both opening practice sessions for the Singapore Grand Prix.
On the floodlit street circuit, damp after heavy afternoon rain, the two-time defending champion clocked 1min 50.566sec in the first stint and then lowered it to 1:48.340 in the later run.
McLaren's Jenson Button was second quickest in the later session followed by the championship leader, Fernando Alonso of Ferrari. Red Bull's Mark Webber was fourth fastest with Lewis Hamilton placing fifth.
Vettel, Formula One's youngest double champion, lies fourth in the season standings and 39 points back from the pace-setter, Ferrari's Fernando Alonso, with seven races to go.
With McLaren's Hamilton and Button sharing the last three race wins between them, the pressure is on Red Bull to fix reliability issues which have plagued Vettel and keep him back in the championship race.
Force India pair Paul di Resta and Nico Hulkenberg were sixth and seventh fastest in the later run, with Mercedes' Nico Rosberg, Ferrari driver Felipe Massa and Lotus pilot Romain Grosjean rounding out the top 10.
Next year's Singapore Grand Prix remains "subject to confirmation". reports said on Friday, as organisers head into high-stakes contract talks with Formula One supremo Bernie Ecclestone this weekend.
The glittering night race is set for its fifth edition on Sunday but the hosts are stalling on a five-year extension, after complaining the present deal is financially unappealing.
On a provisional Formula One calendar for 2013, Singapore is one of four races marked "subject to confirmation", along with New Jersey, Germany and South Korea, according to Autosport.com.
The floodlit grand prix has rapidly established itself as a favourite on the Formula One circuit. But it is one of several venues eager to reduce costs during an enduring worldwide economic slowdown.