Ferrari's Kimi Raikkonen on the Marina Bay street circuit

Singapore (AFP) - Kimi Raikkonen powered his Ferrari to the fastest lap in Friday’s second practice for the Singapore Grand Prix, but teammate Sebastian Vettel had his session cut short after he smacked a wall.

Raikkonen, who will leave Ferrari for Sauber at the end of the season, sped round in 1 minute 38.699 seconds, almost a second quicker than last year’s pole position time.

Championship leader Lewis Hamilton was next at just 0.11 seconds behind after bolting on the fastest hypersoft tyres along the spectacular Marina Bay street circuit.

Mercedes, who usually struggle for pace in Singapore, had elected not to use them in the first session when Hamilton had been only sixth.

But under the lights in the second session, Hamilton found enough pace to close the gap to the Ferrari and finish more than half a second ahead of Max Verstappen and Daniel Ricciardo, whose Red Bulls traditionally thrive on the high downforce circuit.

Vettel limped back to the pits only ninth fastest after breaking a hydraulic pipe when he bounced off the wall, damaging his right rear and front wheels with 40 minutes of the session remaining.

It meant the German, who is 30 points behind Hamilton in the standings, was only able to complete 11 laps under lights in race-simulation conditions, severely hampering his preparations for Sunday’s grand prix.

Valtteri Bottas was fifth in the second Mercedes, less than a tenth of a second behind Ricciardo, with the Renault of Carlos Sainz sixth.

Earlier Singapore specialist Ricciardo, who has finished second for each of the past three years, had led a Red Bull one-two in first practice.

Charles Leclerc marked his first session since being announced as Sebastian Vettel's new teammate for 2019 with a blunder near the end of the session

Ferrari’s new signing Charles Leclerc had a moment to forget when he crashed his Sauber near the end of the first stanza.

The 20-year-old from Monaco misjudged his exit from the Anderson Bridge, clipped the wall hard at turn 13 and destroyed his right front wheel.

The Marina Bay track has 23 corners – more than any other on the current Formula One calendar – and is a severe test for both drivers and cars, with temperatures regularly topping 30 Celsius during the night race.