Chris Walker-Hepburn on the opening backstroke leg, can he give Adam Peaty something to work with on the second? 

He starts strong, but Ryan Murphy of USA is on fire - that's a world record.

Peaty time.

Can he make it 23 golds?

Denise Lewis
Olympic heptathlon gold medallist on BBC TV

It is going to be thrilling, it is going to be anxious, but Jess will know what she has to do and she will go out hard.

Jess is so professional, she will know what time she will have to go through in 200m and know what she has to go through at 400m.

Adam Peaty, winner of Britain's first gold of these games and one of the new school of swimming heroes, will be hoping to add to his Rio medal tally also. 

Who will have the final say at this Olympic meet? 

They're on their way to the poolside, we don't have long to wait.

Image source, BBC Sport

That's how he saves so much money! He does all his shopping in the middle of the night

That was the 1000th gold medal for America in summer Olympics. Not bad.  

Could the man to claim the 1001st be a certain Michael Phelps?

His incredible Olympic journey has taken further steps into the realm of legend in Rio. This final swim gives him the opportunity to secure his 23rd Olympic gold. 

An unbelievable story. Can he write one final chapter?

Take a look at this emotional Greg Rutherford interview where he discusses about being 'gutted' to have a bronze medal.

America lead on the final leg, Simone Manuel to swim for gold. 

Team GB in seventh, too much to ask for Fran Halsall. Who'll get the medals. It's so tight.

A tearful Greg Rutherford, the Olympic long jump gold medallist in 2012, but a bronze medallist in Rio, has been talking to BBC One.

He says: "I never thought I would be disappointed with a bronze medal but I'm gutted. I am in shape to jump very far and it is very frustrating when you don't feel you have done yourself justice. There was no one that was unbeatable.

"I came to these championships to win, I don't come to finish third. I gave it everything I could, but it just wasn't to be. Two Olympic medals in your career is not too bad but I really wanted to regain my title.

"For me, it is always about my family and I spend too much time away from them and you want to make them proud. You set yourself up to win these things and tonight is very disappointing. I wanted to bring home that gold medal. Sorry."

A massive stint by Yulia Efimova for Russia, they lead from America, GB in sixth at the halfway stage.

Very open race so far.

Great Britain in lane eight, Georgia Davies on the first leg, backstroke, keeping touch with the heavy hitters. 

Denmark start strongest though, Australia, then Canada, no hot favourites America in the top three at the first turn. Can team GB get in the medal spots?

Denise Lewis reckons that a 10-second gap is not beyond Jess. "It sounds a lot," she says, "But she has two laps..."

We're seeing images of the call room at the moment. Chad le Clos is shadow boxing inches from Michael Phelps' face, while the great man listens to music and grins. He really is a changed man.

We'll see him in an Olympic pool for the final time very shortly. It's sure to be emotional.

First up, the women grace this Rio pool one last time.

Jamaica win gold but it is not favourite Shelley-Anne Fraser Pryce who has to settle for bronze.

It is a brilliant race from Elaine Thompson who takes gold with a fantastic time of 10.71 seconds.

Tori Bowie of USA takes silver

On the track now is the women's heptathlon 800m. Goodness me it promises to be exciting.

The first heat is under way and it's all about number three.

Jessica Ennis-Hill needs to beat Nafissatou Thiam by approximately 9.47 seconds to retain her title.

Unlikely? Perhaps. Impossible? Nope. 

BBC Radio 5 Live

Greg Rutherford on BBC Radio 5 live: "It's frustrating. I came here to win but couldn't quite get it together. I am very frustrated with a jump they called a foul but it wasn't and it wasn't until the end they changed that.

"But equally I didn't jump far enough and that's difficult. I am pleased I went from fourth back into a medal position but bronze is not good enough for me.

"I am very disappointed."