Marlon Devonish
Former 4x100m gold medal medallist on BBC Radio 5 Live

It's going to be a fantastic race, the key thing to remember is how you go through the rounds - it's imperative you do your best to keep things calm and collected in the heats, then go all guns blazing in the semi-final to reach the final.

Dame Jessica Ennis-Hill
London 2012 Olympic heptathlon champion on BBC TV

Dina is ambitious, she has got a process and she has followed that to an absolute tee. She needs to stay very focused and very relaxed in this semi-final.

So, the first 100m semi-final is about to get under way and Dina Asher-Smith lines up in this one.

She's got a tough challenge in the form of Elaine Thompson-Herah, the reigning 100m and 200m Olympic champion.

The Jamaican is the fifth-fastest 100m runner of all time.

Lutalo Muhammad
Two-time Olympic Taekwondo medallist on BBC Radio 5 Live

The women's 100m could be the biggest event of these Games, we have a really strong field and we are guaranteed to see a fast time.

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

Image source, Reuters

This women's 100m is the race of this championships - and we're starting off with it on day two of the athletics, which is great to get it off to a fantastic start.

There are five, six women who have a real chance of a medal here in this 100m.

One of the great things about athletics is the competition. We talk so much about world records and in the last races, we knew who was going to win it, and if they will win it again.

But this is what's so amazing about athletics, when you have 10 people in a bar and they have 10 different opinions about who is going to win this race - that's amazing!

And that's what we are going to see today.

Seven minutes until Dina Asher-Smith's semi-final.

To the track we go!

Kazakhstan's Elena Rybakina is a set and a break up in the women's bronze medal match, taking the opener 6-1 against Ukraine's Elina Svitolina and edging ahead 3-2 in the second with her serve to come.

More bad news for Novak Djokovic.

He's pulled out of the mixed doubles bronze medal match citing a shoulder injury.

That comes after he lost the singles bronze medal match earlier on today.

The world number one leaves Tokyo empty-handed.

Wow! What an end to normal time!

For a second it looked like Max Gradel had won the match for the Ivory Coast!

Immediately the Spanish coach responded by bringing Wolves forward Rafa Mir into the match and what does he do?

He only blooming equalises with his first touch of the ball!

We are in extra time here... It's going to be tasty.

HT: Japan 0-0 New Zealand

Elsewhere, the second of the four quarter-finals has hit half time with hosts Japan all square and goalless against New Zealand.

Kick off: Brazil 0-0 Egypt

This one has just kicked off too so we will try and keep eyes on all three for you. Anyone got another screen I can borrow?

Just joining us? Well firstly, where have you been...

Secondly, let's have a catch-up on what you've missed so far on day eight.

• Great Britain have shown they are really good at mixed relays overnight. The inaugural Olympic triathlon mixed relay title was followed by Britain clinching the swimming 4x100m mixed medley relay in world-record fashion.
• Emma Wilson claimed a bronze in the women's windsurfing event.
• Good news in eventing, Great Britain sit in the gold medal position.
• GB have missed out on a bronze medal in the women's rugby sevens, beaten 21-12 by Fiji.
• Great Britain boxer Lauren Price has guaranteed at least a bronze medal.

Missed yesterday's heats? Fear not, I've got your back.

If you're still pondering whether to watch the women's 100m action (and I'm seriously questioning your judgement if you are), my colleague Ellie Thomason has put together this feature just for you.

She's given you FIVE whole reasons why you should tune in to watch. No excuses now.

So today is the day. The women's 100m final.

Usually it's the men's 100m we're getting excited about but this year it's the turn of the women. This is the blue riband event of the Tokyo 2020 Olympics.

Can Dina Asher-Smith be among the medals? Hit the thumbs.

The big news in athletics this morning is that Nigerian sprinter Blessing Okagbare is out of the Olympics after being suspended for failing a drugs test.

She had won her 100m heat on Friday and was due to race in the same semi-final as Dina Asher-Smith today.

The Athletics Integrity Unit (AIU) said the 32-year-old had tested positive for a human growth hormone following an out-of-competition test on 19 July.

Image source, Getty Images

Image source, Reuters

GB's Abbie Brown, speaking to BBC Sport: "You have the highs and the lows but you go through a journey with incredible people - and we've been on an incredible journey.

"We've had a bigger, wider squad, everyone plays a part in it, not just the team that was out there today. Family, friends, thank you for always being there and supporting me because I wouldn't be stood here now.

"And the national trust for funding us. It's huge, it's bigger than us and hopefully we've inspired some younger girls or boys to pick up a rugby ball and start playing."

Image source, PA Media

GB's Jasmine Joyce, speaking to BBC Sport: "You can probably tell by all our faces we are absolutely gutted.

"As a squad, we're Team GB, we are three different nations, and we have only been together for four-five months.

"Six months ago none of us had anything: we didn't have jobs, nothing, so to come out here and come fourth place and push New Zealand right to the end, beat USA in the quarter-final and unfortunately lost to Fiji - who are a very good side - unfortunately [New Zealand] were the better team today.

"I can't be prouder of the girls and we've definitely put our programme in a better place. We can call ourselves Olympians.

"Credit to all of us for having nothing after six months and performing here. It's a lot more than us coming here and getting the silverware, it's about putting the sport in a better place and inspiring the nation and giving that little girl a chance to dream big and become an Olympian."

But before we look ahead, let's look backwards. There has already been some athletics action today in Tokyo.

Earlier on, Team GB sisters Cindy Sember and Tiffany Porter both qualified for the semi-finals of the women's 100m hurdles, both finishing fourth in their respective races to progress to Sunday's next stage.

You can read more on that here.

Image source, Getty Images

We've got a very exciting few hours coming up. So grab a cuppa, maybe some biscuits, and park your bum in front of the TV because you won't want to miss a minute.

So what's on the agenda over at the Olympic Stadium?

• Women's 100m semi-finals (from 11:10) - Dina Asher-Smith, Asha Philip and Daryll Neita are involved.
• Men's 100m heats (from 11:45) - GB's Zharnel Hughes, Reece Prescod and CJ Ujah compete for a spot in the next round.
• Women's 800m semi-finals (from 12:50) - Jemma Reekie, Alex Bell, and Keely Hodgkinson race for a place in the final.
• 4x400m mixed relay (13:35) - GB's quartet go for gold
• Women's 100m final (13:50) - the one we've been waiting for...

Thanks Gary, a stellar shift as usual.

Hello everyone, fancy some athletics?

Right that's all from me as, having been on the go since 2am, I am increasingly concerned that what I am writing is in danger of becoming incoherent gibberish (more so than usual anyway).

Lots still come today so I'll hand over to Katie Falkingham to guide you through it all.