Image source, Reuters

This would be a heck of a shock if Japanese superstar Naomi Osaka goes out of the women's singles against Marketa Vondrousova.

After losing the first set in 24 minutes, the four-time Grand Slam champion hit back by immediately breaking the Czech's serve in the second.

But Vondrousova wiped out that deficit for 2-2 and the pair remain on serve.

Nervy moments ahead for Osaka - and for the whole of the host nation.

Simon Mason
Ex-GB Olympic hockey player on BBC TV

Great Britain creating very little now.

Just the five total shots for Great Britain compared to Germany's 18.

Signs of frustration from Great Britain team. Nothing has really gone for them today and the sooner this match is over the better.

Ronald McIntosh
Boxing commentator on BBC TV

Caroline Dubois with a unanimous points victory on her Olympic debut.

She will face off in the round of 16 against America's Rashida Ellis.

That will do nicely for Caroline Dubois.

The Team GB boxer puts in a really encouraging opening display against a difficult opponent and it is a unanimous points decision in the 20-year-old's favour.

She takes all three rounds. Great stuff.

Image source, Getty Images

Simon Gleave, head of sports analysis, Nielsen Gracenote: "Georgia Taylor-Brown's silver medal in the women's triathlon was Great Britain's seventh in Olympic triathlon.

"No other country has won as many Olympic medals in the sport. A silver medal is the best British performance in Olympic women's triathlon, beating Vicky Holland's bronze in Rio."

Ronald McIntosh
Boxing commentator on BBC TV

So two rounds in the book and the opening two rounds scored unanimously for Caroline Dubois. And look at the start in the third round.

A solid, dominant start from Caroline Dubois against Kosovo's Donjeta Sadiku, and she looks to have taken the opening two rounds.

Dubois' coach tells her she must get closer in the third and final round here, but she looks well in control so far.

Surely not from here. The Germans punish some more loose defending from Great Britain to score again.

It's that man Florian Fuchs again although it looks like the final touch was off Liam Sandford.

Kate Richardson-Walsh OBE
Olympic gold medal winning hockey player on BBC TV

The quality they have shown in the first two games is the team pace so using the passes, using each other.

They certainly started the game in that manner but it's just tailed off.

Whether that's running off the ball - making sure there's options there.

They're being made to do a lot of defensive work, making it harder for them when they have the ball.

Great Britain’s Caroline Dubois has had a stellar undefeated junior career which saw her win gold at the Youth Olympics and Youth World Championships, and she was the 2019 BBC Young Sports Personality of the Year award winner.

The BBC’s boxing correspondent Mike Costello has said: “I am tempted to call Caroline Dubois the best female boxer I have seen.”

She's making her Olympic debut and is taking on Donjeta Sadiku of Kosovo in the first round.

Kate Richardson-Walsh OBE
Olympic gold medal winning hockey player on BBC TV

These are the fine margins.

They seem insignificant but Sam Ward was just caught a little bit on the outside initially.

Should be tucked in - doesn't - is late to it and allows them to get the cross down that baseline

And that is really what the Germans do best!

BBC One

Dan Walker and Sam Quek will guide you through the early day-four action from 06:00 BST on BBC One.

You have options mind if you have to drive to work (or back from it in my case).

BBC Radio 5 Live's Olympic Breakfast kicks off at the same time.

Mark Chapman and Rachel Burden will be on hand to provides updates on the overnight action and follow the taekwondo semi-finals, women's diving, women's mountain bike, tennis and boxing.

Simon Mason
Ex-GB Olympic hockey player on BBC TV

Easy goal for Germany.

Great Britain less focused, they left the back post and suddenly the gap is two!

Simon Mason
Ex-GB Olympic hockey player on BBC TV

What a finish that is, that is outrageous from the baseline!

I think he flicked it but he's gone through it, he's put it over Ollie Payne's head!

Germany edge ahead. Jan Christopher Ruhr smashes a shot into the top corner from a tight angle.

Great Britain are wobbling. They were all over the place defensively then.

Wow. Naomi Osaka - the poster girl of the Games - has to climb the tennis equivalent of Mount Fuji.

The Japanese second seed is out of sorts so far in her second-round match, having lost the opening set to Czech Marketa Vondrousova in just 24 minutes.

Vondrousova, a 22-year-old left-hander who is ranked 41st in the world, took three of her six break points in a dominant performance.

Image source, Reuters

As we edge ever closer to Britain's Bianca Walkden competing in the quarter-finals of the women's +67kg category of the Taekwondo, this is well worth a watch....

The 2019 world champion Italo Ferreira is in the final against the home favourite, Kanoa Igarashi.