What a night for Great Britain in the pool. The fact our hashtag #bbcrio2016 has gone quiet suggests the vast majority of you who were following have dived under the duvet to get some sleep. 

That's as good a reason as any for us to bring things to a close tonight. I'll leave you with the schedule for day five and we'll be back in a few short hours for more Olympic action.

Until then, see you later.

Andrew Willis' celebrations tonight will have to be pretty muted, he's back in the pool on Wednesday for the 200m breaststroke final.

Out of the water and on the road, Emma Pooley, Chris Froome and Geraint Thomas are all on their bikes for the road cycling.

Here's how the medal table looks after day four comes to a close. United States move top while Great Britain are 11th.

Duncan Scott: "I felt I had to step things up this year. It's unreal to win. We fought with everything we had."

Stephen Milne: "I can't believe it. These guys were amazing and it was a real honour to swim with them."

Dan Wallace: "I was lucky to make the team and knew I had to step it up and did that tonight."

James Guy: "The first few days were tough for me. I've got faster and faster the more I've been racing. The team is young and we'll be ready for the title in Tokyo."

Crikey the GB relay team looks young. Duncan Scott chews his nails nervously as he waits to be spoken to by BBC Sport's Nick Hope.

Let's see what the lads have to say...

Mark Foster
Former freestyle world swimming champion on BBC One

As a country we have improved so much. We have strength in depth and there's character in the team. The future is bright.

Rebecca Adlington
Double Olympic gold-medal winning swimmer on BBC One

I think this is the best we have done for a very long time and we still have some big races to come. I am thrilled for James Guy especially because this is extra special after the week he has had.

Image source, EPA

Ramp up the cute-o-meter to 10. Here's the moment Michael Phelps celebrated winning gold with his baby Boomer. 

All sorts of emotions in the Olympics Aquatics Stadium. What a night.

Just got up? Then you can watch GB win silver in the 4x200m Freestyle Relay, while Michael Phelps wins his 21st gold, by clicking on the below video.

Six medals so far, four of those in the pool...

Siobhan's father, Sean O'Connor,on BBC One: "If she could stay fit and well I was hoping she'd get a silver medal and she showed it. But I didn't expect the time.

"She has a condition but she never moans and has had a good block of work this year and you can see what she's capable of when she's fit and well.

"Siobhan coming away with a medal, I don't think it'll get any better for me."

Siobhan-Marie O'Connor, speaking to BBC One: "It feels pretty unreal. I am trying not to cry but it is the best feeling in the world. It doesn't seem real but seeing my family I was getting choked up. It means everything, I have worked so hard for it. It has been tough but it is so, so worth it. 

"Sometimes you think 'is it my time'? It just shows what determination can do and all the hard work has paid off but I would not have been able to do it without my amazing team."

Rebecca Adlington
Double Olympic gold-medal winning swimmer on BBC One

Siobhan is only 20 and has another Olympics in her. She has progressed so much that I have no doubt we'll see her in that gold spot on the podium.

Worth remembering that Siobhan-Marie O'Connor was diagnosed with ulcerative colitis in 2013 - a condition that can leave her feeling run down and susceptible to illness. 

It's clear it means so much to her and her family as Siobhan and her dad struggle to hold back the tears.

GB's Siobhan-Marie O'Connor is receiving her silver medal now and is smiling from ear to ear. She fought for that one, fully deserved.

You can watch her excellent swim in the women's 200m individual medley swimming final below.

Rebecca Adlington
Double Olympic gold-medal winning swimmer on BBC One

From now it is a rule that James Guy has to go in the final leg. He was so good.