Andrew Pozzi came out fast, skimmed the hurdles perfectly, until the ninth barrier where he was snagged.

That caught up with him in the final 10m and he is ambushed by another three at the death.

He drops out of contention.

Image source, Getty

Andrew Pozzi was the fourth fastest qualifier from the heats. Only Colin Jackson and Tony Jarrett have been fastest over the high hurdles for Great Britain after he clocked 13.14 in Paris earlier this year.

American Davon Allen and Jamaica's Hansel Parchment will be his main competition for the top slots straight into tomorrow's final.

Colin Jackson
Two-time world 110m hurdles champion on BBC TV

This was the red hot 100m hurdles semi-final heat. There was so much potential. McLeod is the fastest in the world and his technique has improved a lot. He has a really god balance now.

The reigning world champion Sergey Shubenkov and Olympic silver medalist Orlando Ortega are both going to have to wait on the clock.

The second semi-final is incoming...

Kelly Sotherton
Former British heptathlete on BBC Radio 5 live

You have to learn to park mistakes in the past and move on. There's nothing you can do about it, you have to think about how you can rectify it in the future.

Image source, PA

Holly Bradshaw, perhaps spooked by a whisper of a crosswind, flunks her second attempt at 4.65m.

She is still in bronze medal position, but could do with more.

Omar McLeod takes the win and taps his temple. Garfield Darien of France takes second ahead of Orlando Ortega of Spain.

Image source, Getty Images

A punchy opening semi-final in the men's 110m hurdles with Jamaican Olympic champion Omar McLeod and the man who finished directly behind him Orlando Ortega of Spain.

And just for good measure the reigning world championSergey Shubenkov - Russian, but representing the neutral team here after his nation's excommunication - is in lane nine.

Juventus and Italy goalkeeper Gianluigi Buffon has posted a heartfelt tribute to Usain Bolt on his Instagram page.

"Every story has its end. And when the beginning is extraordinary, the end has to be one to remember," he wrote.

"The fastest man of all times, the lightning of athletics retires. Inevitable. And yet incredible. As it has been his entire career.

"But in life you never really stop running. You just do it on a different track. So keep on running Lightning Bolt. While the world still tries to reach you."

Demish Gaye of Jamaica joins Isaac Makwala as an automatic qualifer and Gil Roberts third place is not good enough to get one of the fastest loser spots.

One of those get-out-of-jail-free cards goes to Fred Kerley.

That is going to be one heck of a final.

The cream rises to the top.

Isaac Makwala has a cakewalk down the home straight, checking out the opposition on the big screen.

Not a lot to worry about back there for the Botswana athlete.

The first blemish on Holly Bradshaw's copy sheet as she nudges the bar from it's mooring in her first attempt at 4.65m.

Image source, Getty Images

Isaac Makwala of Botswana became the first man to run a sub-44-second 400m (43.92) and a sub-20-second 200m (19.77) on the same day in Madrid earlier this season.

He also pushed Wayde van Niekerk hard in the 400m in Monaco, finishing just 0.11 seconds behind.

American Gil Roberts is the likeliest contender to take the second automatic qualifying spot.

This was a lactic-fest of a semi-final.

Allison Curbishley
BBC athletics expert on Radio 5 live

Wayde Van Niekerk was trying to conserve as much energy as he could, but he had Thebe inside him and so found another gear.

He's a beautiful runner. I can watch him run all day, every day. He ran past Thebe, gave him a glance and just moved on.

Steve Cram
BBC athletics commentator on BBC TV

What a run by Matthew Hudson-Smith. What a time to run a season's best. This event is really warming up.

A season's best time of 44.74 for Matthew Hudson-Smith. But that is outside the fastest loser spots.

A waning LaShawn Merritt is down in seventh and out.

Image source, BBC Sport

Not as first as the first semi-final, but Wayde van Niekirk and Baboloki Thebe were able to jog home the final 40m after breaking clear of the rest.

A storming run from Matt Hudson-Smith in lane two, but he is nipped to third by Abdaleah Haroun at the death.

Elaine Thompson gets lane six for the women's 100m final at 21:50 BST. Marie Jose Ta Lou is inside her in four.

Wayde van Niekerk trotted to victory in the heats, the world record holder, world champion and Olympic champion looking in imperious form.

This should be more of a challenge.

He has American LaShawn Merrit - who won silver at Beijing - and Botswana's Baboloki Thebe - the fourth fastest man in the world this year - in his semi-final.

Great Britain's Matthew Hudson-Smith is going to have to find some gears to bag a final spot with only the fastest two going through by right.