David Weir's name is announced to the crowd who respond with rapturous applause.

This race is probably going to come down to a straight slug-out between the Londoner and his Swiss rival and the world record holder Marcel Hug.

Weir is coming off the back of an electric performance at the recent European Championships in Italy.

Richard Whitehead is planning some fireworks to rival the opening ceremony's in Rio...

Canada's Brent Lakatos fires up the nitro boost and comes storming through to win in a time of 14.31, just outside his own world record 14.14.

Great Britain's Paralympic champion Mickey Bushell of Great Britain finishes in third, edged out by Ariosvaldo Silva of Brazil.

Image source, PA

Canadian Brent Lakatos, the world record holder and world champion, goes up against Paralympic champion Mickey Bushell of Great Britain.

Lakatos is married to British Paralympic long jumper Stef Reid while Bushell is back in action after a couple of tough years with injury and illness.

Swiss favourite Manuela Schaer takes the victory in 3:39.15, but she was pushed to the line by her young team-mate Catherine Debrunner.

Britain's Jade Jones takes third in a time of 3:41.

Next up on the track is the women's 1500m T54.

Great Britain's Jade Jones is the home-crowd's favourite.

Image source, PA

David Henson, who finished third in the men's 200m T42, on More4: "For me I'm not selected for Rio yet but I feel confident. I'm learning all the time and I'm improving in the way I perform. I've adjusted from being a soldier to being an athlete. It's a big change but I feel like it's going well."

Jessica Ennis-Hill will compete in the long jump today alongside domestic heptathlon rival Katarina Johnson-Thompson and Great Britain's event specialist and world silver medalist Shara Proctor.

That is the first Diamond League event of the afternoon with the first buttocks grazing on sand from 14:15 BST.

Not at his best but still good enough. Usain Bolt romped away in the 200m and then had some sharp words for American rival Justin Gaitlin in his post-race press conference.

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Richard Whitehead, speaking to More4: "We've got Rio this year so it's all about being fit for that, but these two guys (Ntando Mahlandu and David Henson) are really starting to come up strong. I was 40 in the week, so things need to be put into perspective but I'm still getting fitter, faster, stronger.

"Mahlandu is a massive talent at 14. And that motivates me to continue. It's really important for the youngsters like him to come through."

Richard Whitehead obliterates the opposition, surging further and further clear as he runs long, strong and fast to smash his own world record with a time of 23.03.

His previous mark was 23.46 seconds so he gave the record books a serious shaving. 

Ntanta Mahlangu, at just 14, sets a new personal best of 23.97 in second with Great Britain's Dave Henson in third.

Image source, PA

Before the Diamond League stars sparkle though it is time for the big names to strut their stuff in the IPC Grand Prix.

First up in the men's 200m T4 featuring Britain's Paralympic, World and European champion Richard Whitehead.

The 40-year-old is the fastest in the world this year after setting a new world record in Germany.

South African Ntanta Mahlangu, who is currently ranked two in the world, and Dave Henson, who captained the GB team at the 2014 Invictus Games, will be his main opposition.    

Image source, Rex Features

First though Mo Farah returns to the scene of his greatest moment.

Even the seats being decked out in the claret and blue of West Ham, can't dampen Arsenal fan Mo Farah's enthusiasm for London's Olympic Stadium.

He is up in a fierce men's 5,000m with Kenyan duo Edwin Soi and Paul Koech alongside American golden oldie Bernard Legat.

Image source, PA

“It’s crazy to think that in three weeks’ time it is going to be the Olympics.”

It certainly is Mo.

In just 21 days time, on Saturday 13 August, Britain's greatest athlete will line up on the startline of the Joao Havelange Olympic Stadium and attempt the first leg of an unprecedented double-double of Olympic distance titles.

Winning the 5,000m and 10,000m in London sent Farah stellar. 

Doing the same again in Rio would be a starting point for conversations about whether he is the best athlete of any nationality ever.