Germany's Nico Rosberg looked forward to 'kick-starting' his season after seizing Mercedes's second successive pole position in qualifying for the Bahrain Formula One Grand Prix on Saturday.

Compatriot and triple world champion Sebastian Vettel joined him on the front row for Red Bull at a circuit where no driver has won from lower than fourth place on the grid in eight previous races.

Ferrari's Fernando Alonso, three times a winner in Bahrain, will share the second row in Sunday's race with Brazilian team mate Felipe Massa after penalties for Mercedes's Lewis Hamilton and Red Bull's Mark Webber.

"Am I surprised? A little bit. It wasn't really clear who was the quickest car over one lap," said Rosberg of his second career pole.

"I really want to kickstart my season. It has really been a rough ride in the first three races and so today's been the first normal qualifying up to now."

Rosberg's only previous pole was in China last year. Mercedes have not had back-to-back poles since they returned as a works team in 2010.

The German driver has retired from two of the season's three races and finished fourth in Malaysia when he was ordered by the team not to pass Hamilton for third place for fear that the cars would run out of fuel.

The son of 1982 champion Keke now has a chance to take the second win of his career, at the circuit where he made his debut in 2006, but he warned that rear tyre degradation would be a concern in the race.

"It's difficult to say if we have enough pace to win the race tomorrow but for sure we're going to try," said Rosberg.

The driver on pole in Bahrain has won four of the past eight races there.

Hamilton was on pole in China last weekend but collected a five-place penalty for an unscheduled gearbox change after damage caused by a sudden puncture in final practice, dropping him from fourth.

The 2008 world champion and supplier Pirelli blamed debris on the track, rather than structural failure of the tyre.

"Rules are rules. I just have to suck it up and deal with it," Hamilton said when asked whether he felt the penalty was fair for something beyond his control.

Webber was fifth fastest for his 200th race but had a three-place penalty as punishment for causing a collision in Shanghai and ended up seventh on the grid after Hamilton's demotion. Massa moved up from sixth.

"It's better to start alongside Felipe than Lewis," said Alonso. "Tomorrow we both need to think about being on the podium."

Vettel leads the championship with 52 points, with Kimi Raikkonen, who qualified in ninth place but moves up to eighth, second on 49 for Lotus. Alonso has 43.

"Congratulations to Nico, it was all his today," said Vettel, who expected most drivers to make at least three pitstops, and some four. "It was clear even with a perfect lap (he) was unbeatable today."

Britain's Paul Di Resta qualified a strong seventh for Force India and will move up to fifth after the grid penalties. Team mate Adrian Sutil starts sixth.

McLaren's Jenson Button starts 10th, alongside former team mate Hamilton.

At the back, Venezuelan Pastor Maldonado failed to make it through the first phase after he and Williams team mate Valtteri Bottas clocked the same time down to a thousandth of a second. The Finn went through because he set his time first.-Reuters