Dwain Chambers says he can steal Olympic champion Maurice Greene's world 100m crown - because he will win the war of nerves in Sunday's final.

The 23-year-old from London took bronze in Seville two years ago when Greene won gold for the second time.

This time he says he has what it takes to destroy the fastest man the world has ever seen.

"Every dog has its day," said Chambers. "Maurice has been at the top for four years, but I believe I can beat him."

Chambers is in the form of his life, having run 10.01secs (the fastest time ever by a Briton in Britain) at the AAAs and clocked a personal best of 20.31secs over 200m at last month�s British Grand Prix.

But he says the battle with Greene will be won or lost in the mind.

"You have to have it upstairs to beat Maurice," he said.

"90% of it is in the mind for me. If the body is willing but the mind is weak then I'm not going anywhere.

"His whole aura can have an effect on your mental focus. If you get caught up in his mind-games then you'll be crushed.

"You can have the best start, a great middle phase and finish, but if you let him get to you mentally, he�s already won the race.

"It's all eye-contact, the way he looks at you, the way he struts around.

"But for me it comes in one ear and goes out the other. I don't pay any attention - I focus on myself. I've been up against him time and time again and it's worn thin.

"I'm not conscious of him any more. I can read him like a book - I know he's going to strut around with his tongue hanging out."

Greene has not been beaten at a major championships for four years.

Even when he has finished second best at a Grand Prix meeting, he has gone on to win the big one later in the season.

This year he has been suffering from tendonitis of the knee, an injury that may yet prevent him defending his 200m title.

But Chambers dismissed whispers that the champion will not be at his best.

"If he's on the line, he's ready to run," he said.

"When Maurice is on the track, I know he's going to cause a lot of trouble, so I have to focus on my job.

"On the line I'm very nervous. All manner of thoughts go through your head.

"I have to keep my cool and run my own race. In the past a lot of athletes have had a problem doing that. Most athletes, if you stick with them for 70 metres, crack - but he doesn't."

Chambers believes there is only one way the world record holder can be beaten.

On times alone, it looks like an impossible task. Chambers' best is 9.97secs. Greene's is 9.79secs - a difference that equates to nearly two metres on the track.

"You have to get out in front of him and hold on for dear life," he says.

"Donovan Bailey defied logic when he won the Olympic in 1996 from a poor start. But in this day and age if you don't get out you get left behind.

"I've been working on my reaction time over the winter, and if I do get my start the middle and the end won't be a problem.

"I'm in a better position this year than I have been in the last three or four years. Maurice has shown his colours this year and shown he can be beaten."