The Ferraris were Mercedes’ nearest rivals, with Kimi Raikkonen third and Sebastian Vettel fourth, while Toro Rosso’s strong Silverstone form continued, with Max Verstappen and Carlos Sainz finishing the session fifth and sixth respectively.
Hamilton put everyone in the shade, however. He was comfortably fastest on the hard tyre - lapping 1.2s faster than Raikkonen, his nearest challenger - and then dropped down to a 1m 32.917s on the mediums. That is underneath Mark Webber's 2013 lap record, and left him with a half-second margin over the rest of the field.
Mercedes managed to get Rosberg out in the final minutes despite a gearbox oil leak, and in spite of traffic he managed consecutive laps of 1m 33.731s and 1m 33.469s to secure second.
Raikkonen shaded Vettel, 1m 33.692s to 1m 33.918s, as the animals went two by two. Verstappen and Sainz were split by fractions of a second, on 1m 34.147s and 1m 34.282s respectively, while the Williams of Felipe Massa and Valtteri Bottas were even closer, on 1m 34.501s and 1m 34.538s, in seventh and eighth.
Daniil Kvyat was ninth for Red Bull on 1m 34.545s, but Pastor Maldonado then broke the symmetry by taking his Lotus round in 1m 34.708s to book 10th ahead of Nico Hulkenberg in the updated Force India on 1m 34.886s. Kvyat's team mate Daniel Ricciardo was 12th, three spots and three-tenths of a second down, on 1m 34.896s.
Sergio Perez was next in 13th for Force India with 1m 35.121s, ahead of Romain Grosjean on 1m 35.246s. The Lotus driver ended the session worried that something had broken on his car after slipping off-track twice.
Sauber's Felipe Nasr headed the first McLaren of Jenson Button, 1m 35.587s to 1m 35.695s, in the fight for 15th - while Marcus Ericsson completed the sub-1m 36s runners with 1m 35.919s.
That left Fernando Alonso 18th - although the Spaniard's best of 1m 36.101s was set early on, and had been enough for him to be fastest temporarily. Alonso was also the only man notably low in the lap count, completing just six tours of the circuit.
Marussia's Will Stevens once again headed team mate Roberto Merhi, the Briton on 1m 37.989s to the Spaniard's 1m 38.285s.
Fourteen of the 20 drivers transgressed running wide through Copse, the exceptions being Hamilton, Maldonado, Alonso, Nasr, Ericsson and Stevens.