By Steve Cram BBC Sport

If the Norwich Union Grand Prix as a whole didn't quite live up to the pre-match billing, Dwain Chambers' performance in the 100m more than made up for it.

This was as good a field as you will see anywhere in the world, and Dwain came home at a canter.

Chambers beat a world class field with ease

Sure, Maurice Greene stumbled at the very start, but Dwain looked like he had more in the tank. It was a brilliant run.

It's one heck of a turnaround from the Commonwealths last month, when all those questions were being asked about his cramp and his start and his nerves as well.

After his win at the Europeans and now this, he really looks like he believes that he could beat Greene every time he goes out there.

If he decides to end his season with this, rather than running the final Golden League meets and doing the World Cup, I would have no complaints.

He will start next year believing he can beat Greene no matter what - and Greene in turn will be a worried man.

Chambers is the man who will scare Greene too. Forget Tim Montgomery - it's Dwain he is worried about.

Greene hasn't been at his best this season, and he has to figure out why. He ran a great time at the US championships, but since then he has had problems all the way through.

In Zurich he was shocking. And this is a proud athlete who hates getting beaten.

He wanted to win at Crystal Palace. Don't think for a second that he is happy to come in third and have the crowd's attention and adoration focused on Chambers.

The doubts will now be festering in his mind over the winter. No matter what he might say in public, the four defeats by Dwain will have drained his confidence.

I can't believe that he wants his backside kicked like this, and from now on we may see a different Mo Greene.

I've always thought that all great athletes get four or five years of dominance. They might still win after that, but they'll never be quite as invincible again.

Greene has been at the top since 1997. That makes it five years at the very top.

Can he come back stronger and faster next year? Or will Chambers continue his progress and succeed him?

It'll be the story of the season next year.