Daniel Ricciardo was fourth fastest, with Nico Rosberg trailing his Mercedes team mate in sixth.
“1.1s off, right?” Hamilton asked his crew. It said everything.
In the first half of the hour-long session it was Kvyat, fastest in FP2, who initially set the pace again, with 1m 47.629s. But by the halfway stage it was the Ferraris to the fore on the soft Pirellis with Vettel on 1m 46.728s and Raikkonen on a more distant 1m 47.571s. Then came Kvyat, Rosberg, Hamilton - who went off in Turn 7 without hitting anything - and Ricciardo. There was no sign at that stage of a Mercedes comeback, and the team tweeted that the pace of their rivals was genuine and very quick... Max Verstappen and Carlos Sainz were in the top ten for Toro Rosso, in seventh and 10th, sandwiching Romain Grosjean’s Lotus and Felipe Massa’s Williams.
As the session entered its second half Ricciardo quickly moved ahead of the Mercedes and Raikkonen to take second place, before being supplanted by his team mate.
Everyone switched to the supersoft tyres in the final 15 minutes, and Ricciardo - the first to take on the softer rubber - jumped ahead, only to be displaced by Raikkonen and Kvyat who undercut his 1m 46.359s best with 1m 46.132s and 1m 46.167s respectively. But Vettel - a three-time winner here - was the star, looking like his old self as he slid round in 1m 45.682s to put the benchmark 0.450s beyond reach.
It turned out that Mercedes had not found the silver bullet overnight, as Hamilton was 1.1s off the leading Ferrari, and Rosberg 1.5s adrift of it.
Putting their troubles into full perspective, Fernando Alonso in the formerly uncompetitive McLaren was only 0.014s off Rosberg, in seventh place… It wasn’t a bad day for the Woking team, as Jenson Button was 13th, the half-second gap to his team mate filled by the understeering Toro Rossos of Sainz and Verstappen, Marcus Ericsson’s Sauber, Valtteri Bottas’s Williams and Nico Hulkenberg’s Force India.
Massa ended up down in 14th ahead of Pastor Maldonado’s Lotus, Sergio Perez’s Force India, Grosjean’s Lotus and Felipe Nasr’s Sauber.
At the back, Alexander Rossi was quicker than Marussia team mate Will Stevens, as they focused on race work after missing much of Friday because of crashes.
So now we know the truth, Mercedes are in genuine trouble here as Ferrari and Red Bull look so much stronger. It’s going to be a fabulous qualifying session…