Alonso leads Hamilton in first Singapore practice

Alonso's flying lap of 1m49.056s beat Hamilton by 0.122 seconds, with Nico Rosberg was 0.027s further back in third.

The Red Bulls of Sebastian Vettel and Daniel Ricciardo, who had been expected to go well here on account of the RB9's prodigious downforce, were fourth and fifth fastest, but were much more active than Alonso on track, completing 27 and 21 laps to the Spaniard's 16.

Rosberg led much of the early running in spite of reporting gear selection problems, and having to remove a loose mirror.

Kimi Raikkonen was the first of the Ferrari drivers to dial in to the circuit, lapping more neatly than Alonso and even briefly topping the timesheets before Rosberg ended his tenure there.

Alonso soon restored the normal Ferrari order, though, and Raikkonen would close out the session seventh fastest with his front brakes on fire in the pits.

At the end of the first half hour, when the teams have to give back their extra set of soft-compound Pirelli tyres, it was Vettel and Alonso who were fastest by a half-second margin from Rosberg.

But with the tyre exchange completed, Rosberg was among the first drivers to head back out on track, once again on the soft-compound tyres, setting a new benchmark nearly two seconds faster then his previous best.

Hamilton responded with a lap 0.027s quicker to 'win' this run, and that was how the Mercedes order remained until the chequered flag.

As Hamilton and Rosberg moved on to race simulation runs with 30 minutes of the session remaining, Alonso found space on track to nail a flying lap 0.122s faster than Hamilton's best.

Vettel made productive use of his new Red Bull chassis to set a time faster than team-mate Ricciardo, though he had a close encounter with the wall at the exit of Turn 21.

Ricciardo moved on to a full-tank race simulation run in the final half hour, undercutting his previous best but also touching the wall while doing so.

It was not all good news for Vettel, though; he suffered a suspected engine failure at the end of the session and stopped in the pitlane.

Toro Rosso showed well on headline times, with Jean-Eric Vergne sixth fastest and Daniil Kvyat ninth, but this was an eventful 90 minutes for the Faenza team.

Vergne required a battery change that put him out of action during the first hour; then, having set his flying lap, he had an ERS failure that ended his session.

Kvyat, for his part, claimed to be being blocked by several other drivers on-track.

McLaren had a new front wing but neither Jenson Button nor Kevin Magnussen were able to make an impression up front, closing the session eighth and 11th.