Australia are ahead with China in second and the American team in third - but Katie Ledecky is coming back strong and is hunting down the front-runner.

Great Britain are in fifth.

Image source, Getty Images

A gold medal is waiting for the team who can ace their way to this 4x200m relay final. The US quartet has been completely change from the opening rounds.

Team GB is at the top of your picture in lane one, but it's the Australian team leading the way in the early stages.

Russell Fuller
Tennis correspondent

What is Andy Murray really like?

It is a question I am frequently asked.

Driven, passionate, emotional, resilient and potty-mouthed are all adjectives regular Murray watchers could turn to.

Mischievous, funny, loyal, polite and indecisive are words I would add, having been lucky enough to develop a professional relationship with him over the past 11 years.

Read Russell Fuller's full column all about the three-time major winner.

BBC iPlayer

Over on BBC iPlayer, attention is turning to the boxing where Ireland's Daina Moorehouse faces Wassila Lkhadiri and her compatriot Jack Marley is up against Davlat Boltaev.

Image source, Getty Images

Andy Murray won his first title in 2006.

He's been on some journey since then. Eighteen years later and he's got 46 singles titles to his name.

That includes three Grand Slam triumphs, two Olympic golds and 14 Masters 1000 titles.

He spent 41 weeks as world number one, and claimed 29 victories over the 'Big Three' - Roger Federer, Rafael Nadal and Novak Djokovic.

The Scot won 739 of his 1001 ATP Tour level matches and wracked up a whopping $64,677,584 in prize money.

Image source, Getty Images

We could see another spectacular Olympic moment for Team USA tonight with swimmer Katie Ledecky returning to the pool after her triumph in the 1500m freestyle on Wednesday.

The 27-year-old has a shot at some Games history, as a medal in the 4x200m freestyle relay would be her 13th overall, a record for a US female Olympian.

Victoria Pendleton
Olympic cycling gold medalist on BBC Radio 5 Live

I think he's given so much to British sport and the Olympics indeed. I've been lucky enough to meet Andy on a few occasions and he has always been humble, driven and kind and that speaks volumes.

His legacy is undoubtedly enormous in the wake of him retiring from sport. He has given his whole body to achieve such great things, and we're all grateful for that.

I just want to say thank you Andy Murray for being such a hero.

Amy Lofthouse
BBC Sport in Paris

"ALLEZ! ALLEZ!" is the chant around the La Defense Arena.

Leon Marchand really does make it look effortless. The turns are so quick, the technique smooth. And unsurprisingly, he's the fastest qualifier for tomorrow's final.

My smartwatch, meanwhile, has just told me that I'm in a loud environment... as if I hadn't noticed.

The butterfly is brutal stroke. Good job it's first in the medley.

Meanwhile, every time Leon Marchand pops his head out of the water, the crowd shout "yo!"

Marchand has already stacked up a few gold medals on home soil and he eases into the men's 200m individual medley final with a time of 1:56.31.

Daiya Seto of Japan is second and Canada's Finlay Knox is third.

There was one person who was not going to miss Andy Murray's Wimbledon farewell.

Former BBC presenter Sue Barker was there for the highs and the lows of his career so who else could be there to speak to the Scot after his final Centre Court match?

Amy Lofthouse
BBC Sport in Paris

Leon Marchand is greeted with a drumroll from high up in the stands as he walks out to a cacophony of noise.

He took this morning's heat a little easier than usual - which isn't surprising, given the efforts of last night.

How will he go here?

Image source, BBC Sport

Naomi Broady
British player on BBC Radio 5 Live and BBC Sounds

The legacy Andy Murray leaves will continue to impact British tennis for decades to come.

The roof is about to blow off La Defense Arena, because here comes French superstar Leon Marchand in the second semi-final.

With Andy Murray's career now over, watch how he came onto the Great British tennis scene labelled as the "new hope of British tennis."

When asked if he was the "new hope" Murray coolly replied, "I think I am."

You can watch Andy Murray: Will to Win documentary on the BBC iPlayer here.

Calling Duncan Scott and Tom Dean. It's time for you to dive in the pool for the first semi-final of the men's 200m individual medley.

The two GB swimmers are off and Scott, who has won six Olympic medals is in third with 25m to go but one final push from the Scotsman and he finishes in second place.

American Carson Foster wins, defending champion Wang Shun of China is third and Dean snatches that crucial fourth place.

Richard Winton
BBC Scotland in Paris

A generation of Scots have learned life lessons in perseverance, belligerence, swearing, and - perhaps most of all - our place in the world from Andy Murray. He is indisputably, defiantly, gloriously one of us.

Thanks, big fella. It’s been wild…

Image source, Getty Images

Image source, Getty Images

Image source, Reuters

Andy Murray's Wimbledon farewell was never going to be a low-key affair on an outside court.

Centre Court was packed for what turned out to be his final match when he partnered brother Jamie in the men's doubles.

And there were plenty of famous faces from the world of tennis who came along to pay their tributes to one of the greats of the sport.

Amy Lofthouse
BBC Sport in Paris

There's about to be a lot of noise inside the La Defense Arena - Leon Marchand is in the second of the men's 200m individual medley semi-finals.

I walked past a number of French fans earlier on the lookout for tickets just to see Marchand. He's become one of the faces of the Games for France, along with rugby sevens hero Antoine Dupont.