Lewis Hamilton ekes out a bit more from his Mercedes to climb above Nico Rosberg and into P4 with 1:46.426. It's a good time, the best set on softs so far, but the Briton isn't completely comfortable.

"Very hot down by my right ankle. Very hot," he says.

Now the two Red Bulls trade places at the top of the timesheet. First, Max Verstappen does a 1:46.229 and then Daniel Ricciardo with a 1:45.872. Both times down on the ultrasofts.

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Getting darker and darker in Singapore. We should be in full night mode in around 10 minutes and Sebastian Vettel asks for the lights on his steering wheel to be dialled down a bit. 

He then goes fastest of all with a 1:46.287, but that's on the ultrasofts with Nico Rosberg having set his time on the harder softs.

Fernando Alonso copies Sebastian Vettel by slamming the side of his car into the wall, resulting in a mini-explosion of pretty sparks. It doesn't deter him from putting in a decent time - 1:48.394 putting him P7.

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As Jack Nicholls has just mentioned on BBC Radio 5 live sports extra, former F1 driver Alex Zanardi won Paralympic gold on Wednesday. 

The 49-year-old hand-cyclist, who won two gold medals at London 2012, finished first in the H5 road time trial in Rio.

Zanardi then won silver in the road race on Thursday - the 15-year anniversary of when he lost his legs after crashing in the American Memorial 500 CART race at Lausitz, Germany, in 2001.

"I feel very lucky, I feel my life is a never-ending privilege," said Zanardi. "Where today you have the Olympic Stadium, on that piece of land they used to have an IndyCar circuit, which is where I won my very first pole position - for a romantic guy like me this is quite special."

Tom Clarkson
BBC Radio 5 live commentator

It's quite scary he has set that time on the soft tyre. They are going to be blistering when they put the ultrasofts on during qualifying.

Nico Rosberg hammers it around the otherwise empty track and vaults up into P1, going eight tenths of a second quicker than anyone else with 1:46.513.

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A brief lull as the drivers pit to hand back their first set of tyres but it doesn't take long for the sound of engines to fill the Singapore air once again. Nico Rosberg is back out with the soft compound tyres on his Mercedes.

This was the moment when Sebastian Vettel 'brushed the wall' a little earlier...

Just two drivers have failed to set a time so far - Romain Grosjean and Fernando Alonso. Grosjean won't get the chance to do either as Haas confirm its session over for the Frenchman.

Now Max Verstappen goes quickest, nudging Lewis Hamilton off top spot by going 0.034s fastest. Just four hundreths of a second separate the top three at the moment.

Jenson Button heads back out after his earlier problems.

Sebastian Vettel pulls off a mighty lap as he moves to within 0.06s of Lewis Hamilton's benchmark time, but he is really testing the limits of the track.

"I brushed the wall at Turn 20," he says over the radio. "[The damage] is just cosmetic." Someone's telling a little porky, judging by the replays. Looked like a fair old whack to me.

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Andrew Benson
Chief F1 writer

For McLaren, this weekend should be a good chance to score some strong points. The car’s power deficit will be less of a handicap around the twisty Singapore streets and the generally slow-speed corners are exactly the sort of bends where the McLaren chassis - about equal third best with Ferrari behind Mercedes and Red Bull - excels. Not only that, but Fernando Alonso, in particular, is absolutely mighty around Marina Bay. The Spaniard, meanwhile, has been hailing the progress McLaren have made already this year, after their dreadful 2015. “This year at the beginning we had a lot of trust,” Alonso said.

“No one had any doubt McLaren-Honda will win sooner or later but to see us competing with some of the teams that was unthinkable some months ago, or even in Spa finishing in front of one Williams and one Ferrari, it was really needed for the team. The factory and everyone in the team now sees this progress after their hard work and now it's extra motivation for everyone as we all know we just need the last step.”

Alonso said that first win, when it comes, will be a “massive achievement”.

Fernando Alonso is sitting in the McLaren garage having a right old chuckle at something. Meanwhile, mechanics are working away on Jenson Button's car, but he's primed and ready to go. He could be back out soon.

Sebastian Vettel's first flyer puts him fourth but he swiftly improves with a 1:47.731 to leap into P2, 0.36 seconds slower than Lewis Hamilton.

Having won four of the previous five races in Singapore, he must fancy his chances of a real shot at claiming his first win of the year.

Meanwhile, Daniel Ricciardo is currently P5, with Max Verstappen P6.

Andrew Benson
Chief F1 writer

One of the first rules for politicians answering negative-sounding leading questions is not to repeat the bad phrase in question. It was a lesson Sebastian Vettel failed to heed on Thursday when asked about Ferrari’s poor season. “It's true that we didn't have a great season so far, but it's also true that it's not a bad, an awful season as some people might look at it,” he said. “We are criticising ourselves first because we haven't achieved what we set out to achieve. We were closing the gap last year and unfortunately the gap to the top is still there. Sometimes bigger, sometimes smaller, but it's still there. Do I have confidence that we will win races in the future? 100%.” 

Like Red Bull, Ferrari are hoping to be closer to Mercedes this weekend than in recent races, although whether that hope is forlorn remains to be seen. “We might have a chance here, plus there's always random things that can happen here,” Vettel said. “I'm not really looking at the different characteristics and saying: ‘This might be the track or this might not.’ That's the wrong approach. You should always try to do your best, aim for the highest. In the end, I'm here to win. That's what I'll try to do this weekend. It might sound optimistic but you never know what happens.”

Nico Rosberg shaves off a couple of tenths of a second of his previous best to move to within 0.3s of Lewis Hamilton's time. 

Fifteen drivers have completed at least one timed lap, but nothing yet from last year's winner Sebastian Vettel or the two Red Bulls.

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