The Silverstone track was damp for the start of the hour, but quickly dried and Force India's Sergio Perez was first to sample dry tyres, just over 15 minutes in. By the time Ericsson lost control of his car exiting Stowe corner, 38 minutes had elapsed and all 22 drivers had set lap times.
The Swede got his left-rear wheel on the exit kerb at around 235km/h in sixth gear, and in a moment his C35 was heading for a big impact with the inside tyre wall. Thankfully that did its job and he was able to get himself out of the wreckage, but the car was badly damaged and Ericcson was taken to hospital for precautionary medical checks, meaning he is unlikely to participate in qualifying.
The session re-started with five minutes remaining, and a late flurry of action saw times tumble. That left Nico Rosberg second, just 0.063s off Mercedes team mate Hamilton, with the Red Bulls of Daniel Ricciardo and Max Verstappen also within a second of the world champion.
Vettel was the lead Ferrari in fifth, with team mate Kimi Raikkonen ninth. Between them were Williams’ Valtteri Bottas, McLaren’s Fernando Alonso and Force India’s Nico Hulkenberg. Toro Rosso’s Carlos Sainz completed the top ten.
Rosberg had set the initial pace with 1m 36.069s on medium tyres, but was replaced by the similarly-shod Vettel on 1m 33.863s, before going ahead again with 1m 33.591s.
Vettel then got down to 1m 33.203s before Mercedes switched their men to softs. Hamilton lapped in 1m 31.286s, Rosberg in 1m 31.331s, then Hamilton clipped his time a fraction to 1m 31.234s. Behind them, Verstappen did 1m 31.760s to Ricciardo’s 1m 32.004s.
After the Ericsson stoppage, Hamilton cut down to 1m 30.904s to shade Rosberg by 0.063s as the German lapped in 1m 30.967s, and Ricciardo jumped ahead of Verstappen, 1m 31.488s to 1m 31.561s. Vettel stayed fifth with 1m 32.049s ahead of Bottas on 1m 32.736s, Alonso on 1m 32.754s, Hulkenberg on 1m 32.798s, Raikkonen on 1m 32.833s and Sainz on 1m 32.889s. All of those times were set on soft tyres.
Right at the end Vettel slowed and radioed in to report further gearbox problems, his car having been given a new box overnight. Should another new unit be required, he will take a five-place grid penalty for Sunday’s race.