Nico Rosberg is refusing to take his lead from Friday's second practice session for granted, saying Mercedes will has "work to do" to claim pole position for the Singapore Grand Prix.
Rosberg topped the evening session under the lights in Singapore, which was the session which gave the first hint of trouble for Mercedes ahead of its bizarre loss of performance at Yas Marina last year. Though he was 0.3s quicker than Kimi Raikkonen this time around, Rosberg thinks it would be wrong to assume Mercedes has solved all its problems just because of one good practice session.
"It's been okay," he said. "We know that this is the best track for Red Bull and Ferrari so we have to be careful and do the best we can. We shouldn't get ahead of ourselves because last year on Friday we looked OK and on Saturday we were nowhere. Let's wait and see."
When he was asked if there is any way of understanding how quick Ferrari or Red Bull will be on Saturday, Rosberg stressed the importance of Mercedes focusing on its own pace first of all.
"Very difficult. Of course we think more or less we understand the situation, but we thought that as well last year and in the end we have to concentrate on ourselves and maximise what we've got."
Rosberg's day was not without drama, as the German went straight on and into the wall at the tight and narrow Turn 18 late in the opening session, losing his front wing in the process. He said it was just a simple error rather than a brake-by-wire issue with his Mercedes.
"Just braked too deep and locked up and that's it. In general the day has been OK, it's been a decent start to the weekend. Maybe we've learnt a few lessons from last year but early days. Even last year on Friday we were looking OK and then come Saturday we were nowhere so let's wait and see.
"We definitely need to keep on working and getting the most out of it for tomorrow and hope that's going to be enough to give Red Bull and Ferrari a run for their money because here for sure is their best track."