Nico Rosberg has admitted that he was surprised to finish quickest in qualifying for tomorrow's Bahrain Grand Prix.

The German took pole ahead of Sebastian Vettel and Fernando Alonso, making it two successive races in which Mercedes have started at the front of the grid.

When asked if he was surprised to finish on pole, Rosberg told reports: "A little bit, yes. It wasn't really clear before who was the quickest car over one lap.

"I was a little bit closer this morning already so I was a bit happier than yesterday, for sure.

"We worked really well as a team overnight to improve the car because yesterday we were really struggling, so that's gone well. But tomorrow's going to be a tough race for sure with rear-tyre degradation, so a lot can still happen."

It is the second time Rosberg has claimed pole position in his F1 career.