Tearful Dina Asher-Smith revealed her Olympic heartbreak after her 100 metres hopes were left in tatters.

The 25-year-old had been tipped to become the first British woman to take an individual sprint medal since Dorothy Hyman in 1960.

But she failed to reach the 100m final in Tokyo after finishing third in her semi-final before admitting she tore her hamstring at the British trials five weeks ago.

The world 200m champion was initially told she would need surgery before a second opinion left her with a race against time to reach Japan.

Asher-Smith, who has pulled out of the 200m next week but will compete in the 4x100m relay, was in tears while talking to the media at the Olympic Stadium about her injury problems.

"It's been a crazy, intense and heartbreaking period. I was in the shape of my life. Without a doubt. I'm not trying to sound arrogant but that is where I was," she said, as Jamaica's Elaine Thompson-Herah defended her 100m title.

"I tore my hamstring at 60m, shut down and ran 10.97 (in the trials).

"The big story of the day was the clock (initially giving her a new British record before correcting) and I was thinking 'I don't care about the clock'.

"My leg was doing something different. I was told that day it was a rupture so that my hamstring and tendon were no longer attached and I would need surgery. It would be three or four months until I walk again and then a year to sprinting.

"That day I was just in floods of tears....that was a difficult 48-72 hours for me. It was insane. At that point I had a statement written, I probably still have it on my phone, ready to go out just before selection. I wasn't going to be selected.

"I was on crutches, off crutches, learning how to fully extend it again, walk, drills, jog, run. We were counting down.

"It was a 3A tear from a German classification. I think that equates to about a Grade 2. Normally the recovery time is six weeks to start training again. So we've done really well."

Despite the bleak prognosis on her injury, Asher-Smith sought a second opinion in Germany by world renowned doctor Hans-Wilhelm Muller-Wohlfahrt.

"I decided to go and see one of the best sports doctors in the world in Germany to just get an opinion on what type of surgery I should have.

"I couldn't get into the country at first, even though I was on crutches and medical exemption I wasn't allowed to travel because of Brexit, Corona. I was in floods of tears at Heathrow thinking I had to get through.

"I get a call from the doctor in Germany saying 'I've looked at your scans and you need to get here because, whilst you've torn it and you're definitely injured, I don't think it is a rupture for surgery. If we get on it and really push there is a chance you will be on the start line in Tokyo'.

"I started crying and called the selectors saying 'select me, select me'."

"We came back to the UK as it was time to fly to Tokyo. I came on the 20th and put on spikes on the 21st and said 'let's go'," said Asher-Smith, who ran 11.05 seconds in the semi final, way below her personal best of 10.83secs.

"I've been dreaming about this for so long that it just was never an option, unless I couldn't stand or do anything on the leg, it wasn't an option for me to pull out, because this is my life.

"I was never put under any pressure. I was very fortunate that everybody understood and were completely going in my direction. I've never faced any pressure. I was able to push back my flight dates and I was able to pull out of races.

"The easiest thing would have been to turn around and say 'I'm not going to get on the plane'. That would have saved my pride, it would have saved everything.

"But at the end of the day I'm an incredibly talented sprinter and I know what kind of calibre of athlete I am."

There was at least a Briton in the final as Daryll Neita finished eighth with Thompson-Herah winning in an Olympic record of 10.61secs ahead of Jamaica team-mates Shelly-Ann Fraser-Pryce and Shericka Jackson.

Asher-Smith will not run in the 200 metres but believes she has enough to compete in the relay.

"I'm doing the relay, 11.05 is incredibly useful in a relay leg, especially with Daryll," she said.

"I think we're a very talented bunch. Me with a few more days of training and Daryll is in fantastic shape. I'm so proud of her. We grew up 20 minutes apart."

Earlier in the day the event was rocked by the suspension of Blessing Okagbare after she failed a drugs test.

The Nigerian was due to run against Asher-Smith in the first semi-final but was sanctioned by the Athletics Integrity Unit having tested positive for Human Growth Hormone.

Team GB did at least see Zharnel Hughes, CJ Ujah and Reece Prescod reach the semi-finals of the men's 100m as they bid to make Sunday's final.

Team GB finished sixth in the mixed 4x400m relay final while Jemma Reekie, Keely Hodgkinson and Alex Bell also qualified for the 800m final.

Hodgkinson said: "I don't think about expectations – we're just here representing our country, to have fun and do ourselves proud out there.

"I just wanted to secure my place on the biggest stage in the world and it's going to be the biggest race of all three of our careers. We really want to do our families proud and people that support us back home proud."