Michael Johnson on the 100m final

By Michael Johnson 400m world record holder and BBC pundit

Chambers has a long way to go to challenge for medals

Dwain Chambers did OK.

I think in the early rounds there was pressure there, but that pressure started to go away a bit in terms of what people were expecting and what he felt like he needed to come here and do.

Take the combination of things and for him to get into the final might have been as much as we could have expected when you look at the big picture as far as trying to train again and trying to get through four rounds, which he hasn't done for some time.

And then there was the mental pressure.

I'm afraid for Mark Lewis Francis because I would hope that he would take this to build from. He mustn't be too relieved at not messing up or at running a season's best.

And he must not think that all the wrong that he's done in past championships has gone. I still remember that, we all still remember that and hopefully he does. So use this as a platform to build on.

When Obikwelu gets going, he has this incredible stride and just gobbles up the track, very reminiscent of Carl Lewis

Ultimately, this was a very weak final.

You saw a lot of inconsistencies. A lot of people who got a good start but couldn't transfer that into a good drive phase.

Francis Obikwelu was the class of the field. He's the only guy that you can take out of there and put into any international track 100m.

You forget that he's the Olympic silver medallist because he doesn't get a good start.

But when he does get going, he has this incredible stride and just gobbles up the track, very reminiscent of Carl Lewis pulling away at the end of a race.

Michael Johnson was talking to Sue Barker on BBC Two