BBC One

And here's GB's Ama Pipi: "I think I did a good job of running my own race, that's what I've been working on. I think I did okay.

"I tend to go out too quick when I'm trying to run really fast, so I'm working on pacing myself and getting round the track the best way I can.

"I knew I was close coming into the line, but I just tried to focus on myself, on my form."

Image source, Getty Images

BBC One

GB's Jodie Williams, who won her 400m heat, on BBC One: "I like to get things done under pressure, that's my favourite place to get things done. I like to learn on the go. Super young in this event, I've been doing it for all of eight months. It's good fun, I'm enjoying it.

"I'm here to compete seriously, I'm not just taking up a lane. That's my mentality - win every round."

Ah, now then. It appears Nicole Yeargin on at least two occasions stepped outside her lane.

We'll have to wait and see if there's an appeal.

Jamaican Stephenie-Ann McPherson claims victory in heat five in 50.89 seconds.

So, one more heat to go before we know for sure whether GB's Ama Pipi will qualify as a fastest loser.

We may have to wait a little longer than that to find out Nicole Yeargin's fate.

Over on the Red Button (or click on the link at the top of this page), Team GB's Jack Laugher is in semi-final action. He's just scored 81.60 points in his opening dive.

The Yorkshireman, who won 3m synchro gold in Rio, finished seventh in his defence of that title with Dan Goodfellow earlier in the Olympics.

James Heatly, who went for a slightly easier dive in his opening round, scores 66.00.

The top 12 will qualify for the final later this morning.

Oh dear! Nicole Yeargin has been disqualified in that heat.

We're waiting to hear exactly why but it could be due to a lane infringement. That would be a huge shame if that's upheld.

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

Yeargin was very good. It's nice to see her not freaking out when everybody came on the inside, she kept her mind, kept her formula. She could have really panicked but she held it together.

Then she put in the work down the home straight - third place.

It's Candice McLeod who is the comfortable winner of heat four in 51.09 seconds... and GB's Nicole Yeargin takes third to make the semi-finals!

It's 52.04 for Yeargin, to qualify automatically behind France's Amandine Brossier.

It's over to Nicole Yeargin now.

Jamaica's Candice McLeod, who has run 49.91 seconds this year, is also in this one but Belgium's Cynthia Bolingo doesn't start.

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

It was a full on charge from Pipi at the end. You've got all this experience out in front of you, she will have seen Allyson Felix and thought: 'Wow, I'm in her heat! Can I get close to her?'

She ran well and put herself in a good position. I think it could be enough to see her through.

Image source, Getty Images

Ooh that is going to be close! The USA's Allyson Felix takes the win in 50.84 seconds, but it's so tight in the places directly behind her, with GB's Ama Pipi in contention...

Roneisha McGregor claims second, and the Czech Republic's Lada Vondrova just edges out Pipi on the line.

Pipi must wait to see if she'll make the cut.

Time for heat number three of six in the women's 400m qualifying.

GB's Ama Pipi is up against American Allyson Felix and Jamaican Roneisha McGregor.

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

Well done Jodie Williams, really good performance there.

On paper, that was a tricky heat to try and deliver a good, solid and sensible performance - that's how Jodie attacked and approached this 400m. She's still relatively young and so she has to learn every time she goes to a major competition.

Image source, Getty Images

There'll be no Olympic final for GB's Ben Williams in the men's triple jump.

He finishes 12th in Group B with a best leap of 16.30m.

In case you missed it not too long ago, GB's Deborah Kerr has sealed her place in the kayak single 200m final later this morning.

Here's how she did it.

No drama for Jodie Williams, who finishes first in what appeared a potentially tricky field.

Williams clocks 50.99 seconds to finish just ahead of Quanera Hayes.

Jodie Williams has Botswana's Amantle Montsho and American Quanera Hayes, who both boast sub-50 second personal bests, for company in this next 400m heat.

BBC One

Jake Heyward, through to men's 1500m semi-finals: "I felt really comfortable. At the Olympics, you can't take anything for granted and you've got to be ready to work hard - even in the heat. I was really happy with how I felt, it was fantastic.

"I'm confident. I'm coming in under the radar, which is quite nice. I'm really excited and I want to see what I can do on the world stage."

Shaunae Miller-Uibo of the Bahamas, who contests the women's 200m final later today, cruises through to the semi-finals in the opening 400m heat in 50.50 seconds.

Next up, Jodie Williams goes in heat two.

Niall Myant
Sailing commentator on BBC TV

Brilliant from Deborah Kerr. That is fantastic, she must have been nervous after the heats yesterday, where it didn't go to plan really, but Kerr has nailed a final slot. What a fantastic start.