Ferrari's Fernando Alonso was 'best of the rest', just four thousandths of a second behind Hamilton, followed by the Williams duo of Felipe Massa and Valtteri Bottas, but it was a session that raised more questions than answers.
The Silver Arrows had appeared to struggle on the soft Pirelli tyre, as Bottas and Massa set the pace with 1m 19.052s and 1m 19.380s respectively. Rosberg and the usual suspects followed very closely, as Hamilton, albeit on a higher fuel load initially than his team mate, sat well down the order.
Kimi Raikkonen, who had earlier suffered a fuel system issue, set the ball rolling with a lap of 1m 18.842s on the supersoft compound, but just as it seemed yesterday that Mercedes had been the biggest loser after the removal of FRIC suspension, Rosberg banged in the fastest lap by far of the weekend to go fastest on 1m 17.779s.
Hamilton’s counter was a difficult 1m 18.380s, a whopping 0.601s down, and his body language suggested he was anything but happy afterwards. He had complained that his supersoft tyres were vibrating slightly, but that didn’t account for his troubled form.
The Englishman’s time undercut the aggressive Alonso by just 0.004s, as Massa headed Bottas in fourth and fifth places on 1m 18.575s and 1m 18.6121s respectively. Right behind them Kevin Magnussen pulled a cat from the bag late on to beat the Red Bulls and Raikkonen. The Dane lapped his McLaren in 1m 18.756s, ahead of Daniel Ricciardo and Sebastian Vettel who struggled to 1m 18.769s and 1m 18.890s respectively. That left Red Bull, who had been expected to carry the fight to Mercedes after their Friday form, either side of Raikkonen whose own session was ended prematurely as Ferrari opted to change a part of his fuel system to avoid further problems in qualifying.
Nico Hulkenberg cheered Force India with the 10th best time of 1m 19.127s, which put him ahead of the Toro Rossos of Daniil Kvyat, who complained of pulling brakes on his way to 1m 19.131s, and Jean-Eric Vergne on 1m 19.470s. Jenson Button was another in trouble, also complaining about his McLaren’s brakes en route to 1m 19.489s.
Sergio Perez couldn’t better 1m 19.505s for 14th in the second Force India as Esteban Gutierrez had a better day to lead Sauber with 1m 19.601s. Lotus continued to struggle, with Romain Grosjean 16th on 1m 20.078s ahead of Jules Bianchi’s Marussia on 1m 20.198s and team mate Pastor Maldonado on 1m 20.466s. Adrian Sutil,who completed just six laps, was next on 1m 20.844s for Sauber.
At the back, Kamui Kobayashi’s repaired Caterham managed 1m 21.018s to head team mate Marcus Ericsson on 1m 23.077s, as electrical trouble restricted Max Chilton to 1m 23.449s in the second Marussia.
The session was characterised by understeer and a lot of harmless off-track moments, for Kobayashi, Bianchi, Rosberg, Ricciardo, Hulkenberg, Button, Perez, Grosjean, Maldonado, Vergne, Vettel, Massa and Gutierrez, while Alonso was the sole driver to actually spin after locking up at Turn 8.