SAKHIR, Bahrain (AP) -- Mercedes drivers Lewis Hamilton and Nico Rosberg continued to dominate the new Formula One season by setting the pace in Saturday's pre-qualifying practice for the Bahrain Grand Prix, while world champion Sebastian Vettel had a rare session-ending spin.
Hamilton, who won last weekend in Malaysia, was quickest with a time of 1 minute, 35.324 seconds at the Bahrain International Circuit, while his teammate and championship leader Rosberg was just one tenth of a second off that pace.
The best of the rest was Force India's Sergio Perez, half a second off Hamilton's time, ahead of Williams pair Valtteri Bottas and Felipe Massa.
Vettel made a mistake that was as costly as it was rare. He ran wide onto a kerb, lost grip and spun backwards into a gravel trap, ending his session.
That cost him any running on the softer tire and the chance to gather data needed to fine tune the car for qualifying later Saturday.
McLaren's Jenson Button was sixth fastest, while the Ferraris of Fernando Alonso and Kimi Raikkonen were seventh and 10th respectively, separated by Force India's Nico Hulkenberg in eighth and Toro Rosso's Daniil Kvyat in ninth.
Qualifying and race begin at 6 p.m. local time as the sun is setting and temperatures falling, meaning the conditions will be markedly different than those for practice. Hamilton's best time on Saturday was a full second slower than the time he set in Friday's night practice.