Brazilian GP: Sebastian Vettel top as Kubica crashes in Brazil practice

Sebastian Vettel led Charles Leclerc to a Ferrari one-two in an incident-packed second practice session at the Brazilian Grand Prix.

The German was 0.021 seconds ahead of Leclerc with Red Bull's Max Verstappen third, ahead of Mercedes drivers Valtteri Bottas and Lewis Hamilton.

Williams driver Robert Kubica began the session with a heavy crash at Turn Three from which he emerged unscathed.

Both Toro Rossos suffered reliability problems, stopping on track.

The session ran in cloudy but grey conditions after the wet weather for the morning session, but Kubica appeared to be caught out by dampness on a painted white line when he spun at the fast Turn Three on his first flying lap of the day.

The Pole, whose Williams had been used by reserve driver Nicholas Latifi in the first session, lost the rear, over-corrected and spun into the wall, badly damaging three corners of the car.

It was another blow for Williams, who have been struggling for pace all year and in recent races have been suffering from a shortage of spare parts.

At the front, the true competitive order is hard to read, as both Ferrari drivers and Hamilton had messy runs.

Vettel and Hamilton were both blocked by Bottas on their fastest laps, the world champion on the exit of Mergulho, the penultimate corner, and Vettel shortly afterwards on the exit of Juncao, just a few metres further on.

And Leclerc did not improve in the final sector of his fastest lap, which suggests he, too, had more time in him.

Verstappen impressed to be just 0.134secs off the pace as Red Bull's revival in the last few races continues, and Bottas was 0.156secs behind Vettel. The compromised Hamilton - whose time, like Vettel's, was set on his second lap on his tyres - was 0.067secs behind his team-mate.

Ferrari may well see the results of the session as vindication after what they consider to be unfounded allegations about their engine in the wake of two rule clarifications from governing body the FIA.

Ferrari insist neither ruling - one governing the operation of the hybrid system and fuel-flow meter, and the other the addition of oil into the combustion chamber - have any effect on the running of their engine.

They said they would be back to their normal form in Brazil after a disappointing race in the US last time out, and at least on Friday they look to be favourites for pole position on Saturday.

Best of the rest was Kevin Magnussen's Haas, for once not struggling with tyre temperature in a disappointing season for the American team, followed by the Renault of Daniel Ricciardo and Alfa Romeo's Kimi Raikkonen.

The second Red Bull driver Alexander Albon, confirmed with the team for 2020 earlier this week, was struggling after a crash at the end of the first session and down in ninth place, 0.9secs off team-mate Verstappen.

At Toro Rosso, Pierre Gasly's engine failed mid-way through the session forcing the Frenchman to park up at Turn Three, while Daniil Kvyat went off at Juncao, the final corner, with five minutes to go, after his car switched off, causing him to spin lightly into the barrier, bringing out the red flag and the session to a premature end. The team said they did not yet know the cause of the problem.

McLaren's Lando Norris was down in 18th place, eight places behind team-mate Carlos Sainz, but the 20-year-old Briton said he made a series of mistakes.

"I'm confident if I put the lap together and don't make the mistakes I did today, it will look a bit better," Norris said.

"It was actually a relatively good day," said Hamilton. "The second session was good, nice and smooth. The Ferraris are quite quick today and they were generally beating us just all on the straights."