Norway's Karsten Warholm canters in in 48.67 with Poland's Patryk Dobek second in a season's best 48.75.

Home favourite Luke Campbell is waiting on a fastest loser spot...

That is the gauntlet laid down to Yasmani Copello of Turkey - the only man to have run faster than that this year.

Image source, Getty

With team captain Dai Greene reduced to cheerleader by a hamstring twang, Jack Green is the sole British representative in the 400m hurdles semi-finals.

Norway's blindside world champion Karsten Warholm goes in the first heat and comes into the championships in fine form after setting a new national and personal best at the Anniversary Games in London last month. His reaction was typically understated.

Look out for Yasmani Copello, once of Cuba, now of Turkey, in the third heat.

He was second behind Warholm in London, won this title in Amsterdam in 2016 and won Olympic bronze in Rio.

Green is also in the third heat.

Top two through by right, another two from across the three semi-finals to progress by virtue of the clock.

If Michael Johnson is confident, I'm confident.

Michael Johnson
Four-time Olympic gold medallist athlete on BBC TV

Dina Asher-Smith looks a different class to the rest of the field. She looks calm and confident. It was a really good, solid effort.

What makes her so good is that her technique is so efficient, so every ounce of energy is used and it propels her down the track.

The only thing she can work on to improve is her foot speed. But there's nothing to complain about for her technique.

This might well be the main threat to Dina Asher-Smith's hopes of gold.

Dafne Schippers - a bronze medalist in the 100m at London 2017 and world 200m champion - has the major championships chops to be a threat.

Massive props to Imani-Lara Lansiquot though. The 20-year-old Briton finished third to book her place in the final.

It is 20:30 BST tonight. Book your slot on the sofa.

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

CJ Ujah reacts well from the gun and then picks himself up well, after that he holds his form and stays relaxed, knowing he had enough to take him into the final. Job done for CJ.

Italy's Filippo Tortu takes the win as he goes toe-to-toe with CJ Ujah and just about holds on for the win in 10.12.

The 20-year-old young shaver has had a stellar breakthrough season.

That is a full house of three Britons into the final at 20:50 BST tonight. Ambitious talk of a clean sweep of the podium though might have to be toned down after Frenchman Jimmy Vicaut's 9.97 blast in the first semi-final.

Agony for Nick Miller.

His season started so well with an 80m-plus throw and gold in the Commonwealth Games.

But after a bout of illness he has struggled to regain his form and he is out of this final.

His opening throw of 73.16m is followed by two no-throws and is not good enough to make the top-eight cut for three further attempts.

Image source, Getty Images

Britain's CJ Ujah - who won five Diamond League races last season to take the top-tier series 100m title - goes in the third and final semi-final.

The 24-year-old has not quite matched that form so far this season. He could come under some pressure here too with Italy's Filippo Tortu and France's Amaury Golitin having both run faster.

Best two automatically through to tonight's final remember, with the fastest two losers across the three semi-finals to join them.

You don't want to be waiting on the maths.

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

Zharnel Hughes looked very impressive. He reacted well at the start and then he picked up well - once you do those things right, with the quality he has - you're in good shape.

Zharnel Hughes' head swivels like something out of the Exorcist over the final 20 metres as he checks and checks again for any contenders.

There weren't any.

Loads in store for the Briton.

Jak Ali Harvey of Turkey takes the second spot.

Image source, Getty Images

Britian's Zharnel Hughes was briefly 2018's fastest man after he clocked 9.91 in Jamaica earlier this season.

That mark has been overtaken globally, but is still good enough to share top slot in Europe so far this year.

He has Turkey's Jak Ali Harvey - previously of Jamaica - for company in this second semi-final.

Hughes grins for the cameras as his name is announced for the Berlin crowd. He looks loose, limbre and ready to unleash.

Let's see...

While the boys do their thing, take a moment to watch Dina Asher-Smith saunter to a 10.93 win in the women's semi-final.

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

Jimmy Vicaut smashed it out of the blocks - he took that 30m very, very quickly - knowing how quickly Reece Prescod finishes.

One of the big things Prescod has to do is to make his start consistent, because he's so quick in the finish. Once he sorts that start out, boy oh boy, the others better watch out.

Denise Lewis
Olympic heptathlon gold medallist on BBC TV

The British sprinters need to adjust to the atmosphere in the arena.

The moment they think about getting medals, the game is lost, they just have to take each round as it comes and make sure they get through.

Jimmy Vicaut came in with injury concerns. They just evaporated.

The Frenchman wins in a new championship record and is a genuine gold threat.

Reece Prescod is slow out of the blocks, but comes through with a trademark express train finish to take the second automatic spot in 10.10 seconds.

Daryll Neita speaking on BBC TV: "It just wasn't there today. It's really disappointing. I know I'm better than that - it sucks.

"I'm just not going at the moment. I'm in much better shape than that, and it's annoying I couldn't show it on the biggest stage of the year."

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

Imani-Lara Lansiquot has produced a great performance here, it's her first run , she hasn't had the chance to build up, so she's done really well.

Dafne Schippers took her time to get up and going, but once she did she really powered through.

Image source, Getty

Well now.

Time for Britain's short-distance speed merchants to show their form.

Up in the first of three semi-finals is Reece Prescod.

The 22-year-old British champion was a finalist at London 2017, beat world champion Justin Gatlin in Shanghai in May and then ran a wind-assisted 9.88 in the United States two weeks later.

Big credentials. But he has Frenchman Jimmy Vicaut - the joint fastest in Europe this year - inside him.

These two and Turkey's Emre Zafer Barnes will fight it out for the two automatic slots for tonight's final. Two fastest losers from across the three semis will also make the 20:50 BST showdown.

Nick Miller has work to do in the hammer.

The Briton registers a no-throw in the second round and his opening attempt of 73.16m is now only good enough for 10th.

He needs to be in the top eight to make the cut for another three throws after the first three rounds.