Hamilton warns Button

Jenson ButtonJenson Button may hold a commanding lead in the world championship as the 2009 reaches its climax but Lewis HamiltonLewis Hamilton knows how quickly fortunes can change in Formula One.

Button's fifth-place finish in Sunday's Singapore Grand Prix enabled him to take a 15-point lead in the drivers' standings with three races remaining.

The Briton heads to Japan this weekend knowing he can be crowned world champion if he finishes five points ahead of Brawn GP team-mate and nearest rival Rubens BarrichelloRubens Barrichello.

However, the outgoing world champion has painful experience of seeing the opposite scenario play out - Hamilton's commanding lead being overhauled by Kimi RaikkonenKimi Raikkonen in 2007.

"Let's not forget, I was leading by 17 points with two races to go and I lost it," Hamilton said in the aftermath of his victory in Sunday's Singapore Grand Prix.

"It's very, very, very tough, right up until the last moment so I just suggest that they all keep pushing and we will see over the next few races but he's done a fantastic job up until now, so I wish him all the best."

Hamilton's team boss at McLaren, Martin WhitmarshMartin Whitmarsh, also has vivid memories of his charge's title tilts over the past two seasons and reasons that calmness is key for Button.

"I am sure he will go away from this event feeling more relaxed, but he will still have some tension," he said.

"It's very easy to crash out at the next event with Rubens winning, which will be a 10-point swing - and we've been there, the last two seasons have been like that for us.

"He just has to stay calm, and if he does not make any mistakes he will win, but that in itself brings tension to you."