Sebastian Vettel headed a commanding Ferrari one-two as Mercedes struggled in a dramatic Practice Two at the Malaysia GP.
In a session of unexpected contrasts at Sepang, Vettel set the pace by 0.6s from team-mate Kimi Raikkonen as world championship leaders Mercedes were also outpaced by both Red Bulls and, in an additional shock, Fernando Alonso’s McLaren.
Lewis Hamilton, who holds a 28-point title lead over Vettel, found the gravel and then finished only sixth fastest, a whopping 1.4 seconds off the pace. Team-mate Valtteri Bottas also spun and finished seventh.
A big crash for Romain Grosjean stopped the session with 16 minutes to go.
The Haas driver was unhurt after being sent on a high-speed collision course with the barriers after a drain cover on the Turn 13 kerb worked loose and ripped the Frenchman’s right-rear tyre apart.
With the action red-flagged, FIA race director Charlie Whiting and local track officials took to the track to conduct an investigation about the drain cover. Replays showed the cover opened after Valtteri Bottas’ Mercedes went over it on the normal racing line.
The early end to the session curtailed teams’ long-run programmes, meaning Mercedes lost valuable time to get to the bottom of their surprise Friday problems.
Red Bull had set the pace in the wet opening session and, although they were outpaced by Ferrari in Practice Two, Daniel Ricciardo and Max Verstappen remained ahead of the Mercedes pair in third and fourth places respectively.
“Mercedes will be very worried tonight, they’re going to have to come up with something different,” said Sky F1’s Paul Di Resta.
Ferrari’s emphatic Friday performance in the dry came in the wake of the events of Singapore, when the team’s championship hopes took a huge blow when Vettel and Raikkonen crashed with Verstappen at the start of the race.
“It was a very difficult session for us. We struggled from the get go this morning, in the wet, in the dry, on all tyres. We need to find out overnight what it is,” admitted Mercedes boss Toto Wolff.
“There is a fundamental issue in the car that we need to find out. And they are very complex so it can be a tiny detail that unsettles the car.”
Mercedes’ travails were underlined by the rare sight of a McLaren-Honda car outpacing them, although Alonso’s fifth-fastest time was in itself a surprise on a fast-sweeping circuit not expected to favour the car’s package. Indeed, team-mate Stoffel Vandoorne finished down in 13th place.
Force India and Renault were closely-matched in the two reaches of the top 10.