Liam Broady, the sole British representative left in the singles, is just getting his second-round match under way.

He's facing Hubert Hurkacz of Poland, who memorably beat Roger Federer in the Wimbledon quarter-finals a few weeks ago.

It's a tough test for Broady. Hurkacz is the seventh seed and entered the top 15 in the world rankings prior to arriving in Tokyo.

Jonathan Overend
BBC Radio 5 Live commentator

She has been caught!

A headshot in the last second and Walkden is out.

I can't believe that, the last kick of the match.

We thought she had it. How can you not think you have it with one second remaining!

Heartbreak for Bianca Walkden!

Walkden is beaten in the dying moments, as Lee Dabin lands a head kick in the final second of the contest.

That is tough. Wow.

Amid all the drama, Bianca Walkden is only two infringements away from disqualification.

But the three-time world champion continues to battle away and edges in front!

It's 23-22 to the GB fighter with SECONDS to go.

We are into the final lap and Evie Richards' chance of a medal have surely gone. The Briton is three minutes away from runaway leader Jolanda Neff. Neff is being chased by two Swiss team-mates Sina Frei and Linda Indergand.

More problems for Bianca Walkden.

There's a lengthy break for a review, as the Korean coach asks for Walkden to be deducted two points for an infringement.

Tense, tense moments.

And it's successful! Walkden trails 19-14 with 50 seconds to go...

Great Britain's Zoe Smith has got her Olympic campaign under way.

The 27-year-old successfully lifted 87kg in her second snatch.

Easing into it.

Jonathan Overend
BBC Radio 5 Live commentator

There's a discipline issue here for Walkden - 7 warning points!

Just a reminder that you are disqualified at 10 warning points.

South Korean Dabin Lee lands a swiped kick to the head to take control at the start of the final round in this semi-final.

Bianca Walkden trails 13-10 after a gam-jeom is taken away.

Trouble as we approach the halfway point of the round, but Walkden stays calm and closes the gap to one point at 14-13.

Steve Bunce
Commentator on BBC Radio 5 Live

They've set themselves up for the end game.

Fighting for redemption, fighting for that place in the final.

This could be the greatest 120 seconds you've ever seen!

Jonathan Overend
BBC Radio 5 Live commentator

It's ramping up after that cagey first round!

Walkden scores right at the end of it.

Bianca Walkden closes the gap to 8-7 as this semi-final begins to heat up after a cagey opening.

Another blow to the trunk keeps Walkden within one point at 10-9 and she manages to draw level in the very last second of the round!

This is finely poised. One round to go. A place in the final at stake.

Jonathan Overend
BBC Radio 5 Live commentator

You can feel the tension around, there's not a lot of noise from either camps.

This one is not all action at the moment, they are very wary of each other.

John Cullen
Former Taekwondo international

It's all about the techniques at the moment.

A couple of fouls and Walkden has her work cut out here.

Three-time world champion Bianca Walkden is up and running (kicking) as she continues her bid for Olympic gold in Tokyo.

And there's plenty of work to do, as a few yellow cards for Walkden gives South Korean Dabin Lee a 3-1 lead in the opening round.

In the build up to the Games Bianca Walkden took on fitness Youtuber MattDoesFitness in a series of physical challenges to test their speed, strength and power - but who wins?

Team GB

And here is what is on its way later today:

• Taekwondo: GB's Bianca Walkden is just about to get under way in her +67kg semi-final.
• Canoe Slalom: GB's Kimberley Woods is into the final of the women's K1 event, which gets under way at 08:15 BST.
• Equestrian: British rider Charlotte Dujardin will be looking to add to her three Olympic titles as she joins veteran Carl Hester and debutant Charlotte Fry in the team dressage (09:00 BST).
• Gymnastics: One of the Olympics' biggest TV audiences will be expected for the women's team final (11:45-14:10 BST). The United States, led by Simone Biles, are the favourites but can Britain get in the mix for a medal?
• Rugby Sevens: Great Britain face the USA in the men's sevens quarter-finals (10:00 BST).
• Weightlifting: Britain’s Zoe Smith competes in the women’s 59kg category (07:50 BST) with Sarah Davies in action in the 64kg class from (11:50 BST).

If you're just joining us, here is a quick run through of everything you've missed so far on day four:

• Swimming: Britain's Tom Dean claimed a stunning gold ahead of team-mate Duncan Scott in a thrilling 200m freestyle.
• Triathlon: Britain's Georgia Taylor-Brown produced a superb run to earn a silver medal in the women's triathlon, fighting back from a bike puncture which left her well adrift of the leaders. Bermuda's Flora Duffy claimed a historic first gold medal for her nation.
• Taekwondo: GB's three-time world champion Bianca Walkden is into the women's +67kg semi-final at 08:00 BST, however compatriot Mahama Cho lost to China's Sun Hongyi in the last 16 of the men’s +80kg.

• Tennis: Japan's world number two Naomi Osaka suffered a shock third round defeat by world number 42 Marketa Vondrousova.
• Tennis: Andy Murray and Joe Salisbury are into the men's doubles quarter-finals

Steve Parry
Olympic bronze medal swimmer on BBC Radio 5 live

Consistency is key as we saw with Daley and Lee yesterday but unfortunately it wasn't the same today.

It was a mesmerizing display by the Chinese!

Jack Laugher to come and Tom Daley goes again so we could have more medals later!

Ross Quinn: Nice that Joe and Andy have just got through. Looks like leaving the singles has been the right choice.