As soon as the fast guys got going, Vettel took control for Ferrari on the ultrasoft tyres, with supersoft-shod Raikkonen riding shotgun. The German got down to 1m 07.307s, the fastest time thus far, with the Finn on 1m 07.558s. Then Ferrari number 7 went ahead with 1m 07.234s.
After some initial brake-locking problems with his Red Bull, Daniel Riccardo joined them with 1m 07.639s ahead of team mate Max Verstappen on 1m 07.761, as Valtteri Bottas got in on the act for Williams with 1m 07.814s and was shadowed by team mate Felipe Massa on 1m 07.831s.
While all this was going on, Mercedes were nowhere, struggling on their ultrasofts.
After 30 minutes, Hamilton was 17th on 1m 10.591s, having insisted on coming in for checks despite being asked to stay out longer, as he felt he was on the verge of an accident. His rears were heavily grained and blistered, after only eight laps. Rosberg was 20th, on 1m 10.959s. Both cars were in the garage, being readjusted.
With Pirelli having dropped the mandated minimum rear tyre pressure overnight, Mercedes were clearly in trouble. Hamilton was three seconds off Vettel, on the same rubber…
Making matters worse, the Haas cars were eighth (Esteban Gutierrez) and ninth (Romain Grosjean). Then Rosberg had a big shunt when he lost control exiting Turn 2, spun and brought out the red flag at 11.38. He had just set the fastest first sector time, and slow-motion footage revealed that the left rear suspension broke, pitching the car momentarily clockwise before it rotated anti-clockwise into the barriers. By then the Mercedes were 19th and 20th…
The session restarted with 12 minutes remaining, by which time the F1 W07 had been recovered as Mercedes prepared for some intense investigation.
Rubbing salt in the wound, Vettel went straight out and banged in the fastest time of 1m 07.098s. Hamilton, however, responded with 1m 07.754s to go fourth. Perhaps things were not quite as bad as they had seemed, especially as he then trimmed that to 1m 07.308s, 0.210s off the outright pace.
Behind the top seven, Force India’s Nico Hulkenberg headed the McLarens of Jenson Button and Fernando Alonso to complete the top 10, as further back Pascal Wehrlein did a bit of a giant-killing job with 13th for Manor as he split the Haas cars.
Both of them were involved in minor incidents; Gutierrez went off in Turn 1, then joined Grosjean, Kevin Magnussen and Sergio Perez by going wide in Turn 8. Bottas spun in Turn 9.
The forecast still predicts rain in qualifying. Wet or dry, it’s going to be a humdinger, all-out battle between Ferrari, Mercedes, Red Bull and Williams.
Mixing up the grid still further will be the five-place grid drop that Vettel is already set to take for a gearbox change. And following his accident, Mercedes have confirmed a new box is needed on Rosberg’s car, hence he too will lose five places.