Lewis Hamilton completed a clean sweep of practice ahead of Sunday's Bahrain Grand Prix following a session in which Sebastian Vettel made a rare mistake.

Under clear blue desert skies and in a balmy temperature of 27 degrees centigrade, Hamilton and Mercedes were again in a class of their own around the Bahrain International Circuit.

The 29-year-old finished with a lap of one minute 35.234secs, just under a second down on his best from practice on Friday, and set in far different conditions.

On that occasion, and for qualifying and the race, the floodlights were switched on as the track was bathed in the glare of 5,000 newly-installed bulbs to celebrate the event's 10th anniversary.

Bahrain becomes a night race, along with Singapore and Abu Dhabi, and at present there is one shining light amongst the field - Hamilton.

Following his victory in Malaysia last Sunday to spark his title challenge into life after a technical failure wrecked the opener in Australia after two laps, Hamilton has so far been stunning over the two days so far in Bahrain.

Again team-mate Nico Rosberg had to settle for being second best, the German finishing 0.115secs adrift, with Force India's Sergio Perez up to third, but just over half a second down such is the gulf between the Mercedes duo and the rest of the field.

Williams' Valtteri Bottas and team-mate Felipe Massa were fourth and fifth on the timesheet, the latter a second adrift, with McLaren's Jenson Button down in sixth.

The key point is that the top six drivers all have Mercedes power in their cars, with Ferrari's Fernando Alonso next up, but 1.1secs down on Hamilton.

As for four-times champion Sebastian Vettel, the 26-year-old German late braked into turn three and went sliding into a gravel trap from which he was unable to recover.

With seemingly little damage to his car, Vettel - who finished down in 21st place - should be on track to comfortably make qualifying.

Only Max Chilton was behind Vettel, the young Briton just over four seconds behind Hamilton - who is now on course to make it three pole positions in a row.

As for the top 10, Nico Hulkenberg was eighth quickest in his Force India ahead of Toro Rosso's Daniel Kvyat and Kimi Raikkonen in his Ferrari.

As for Daniel Ricciardo, who will serve a 10-place grid penalty on Sunday following an unsafe release from a pit stop in Malaysia, the Australian has so far struggled as he was down in 13th, nearly two seconds off the pace.