Nico Rosberg is not expecting to maintain his early advantage over team-mate Michael Schumacher all season - admitting that he never thought he would be able to deliver such strong form.
The German has out-qualified and out-raced Schumacher in the first four races of the year - a feat that few people expected him to achieve.
But despite the early season form, Rosberg says he is taking nothing for granted in terms of how the rest of the year will pan out.
"I'm happy to be ahead of him but I don't know how long it will last," Rosberg told Gazzetta dello Sport. "I would have been content to be at his level. Now I hope I can carry on fighting with him."
Rosberg has also reiterated how much he is enjoying working with Schumacher, having confessed to having some reservations about what life would be like alongside the seven-time champion.
"People probably have the wrong opinion on Michael," he said. "I myself thought that it wouldn't be a good thing to have him as team-mate, when instead I'm positively surprised about it."