So here comes Joe Joyce. After a bye in the first round, this is his first appearance. Davilson dos Santos Morais from Cape Verde is his opponent. Joyce in red, Morais in blue.

Just as it was looking that Kerber was going to level things up, Monica Puig breaks back to make it 4-4 in the second set.

Puig took the first set 6-4 and is hoping to be Puerto Rico's first Olympic gold medalist.

We await the appearance of Joe Joyce. The bout before has over-run slightly. Inconvenient.

With six minutes left of the third quarter, the United States open the scoring at Deodoro.

Michelle Vittese's goal means Great Britain are up against it now if they're to win the game - and with it Pool B - although they are already assured of a top two finish, having won their opening four games.

Angelique Kerber leads 4-3 in the second set of the women's gold medal match, with a break of serve.

The German lost the first set 6-4 to Puerto Rico's Monica Puig.

Puig is looking to win her nation's first ever gold medal.

Speaking of finals, Great Britain's Grace Reid has reached the final of the women's 3m springboard...

And, before that, Juan Martin del Potro came through a thriller with Rafael Nadal to book a men's singles final against Andy Murray.

You can watch the deciding tie-break right here...

Not long ago we saw Jason Kenny win a deciding race against Russian Denis Dmitriev to reach the final of the men's sprint. If you missed it, you can watch it again here... 

British super-heavyweight fighter Joe Joyce takes to the ring at 23:00 BST. 

Davilson dos Santos Morais from Cape Verde stands between Joyce and an Olympic quarter-final.

Watch live boxing here.

It's half-time in the Pool B decider between Great Britain and the United States at Deodoro.

For their part, GB have looked the more likely to score, but if it stays like this they go through second.

Iain Dwyer, British Cycling's track sprint coach is understandably a happy man.

Great Britain are guaranteed gold and silver in the men's sprint tomorrow when Jason Kenny races Callum Skinner. Also, there has been a British gold in the women's team pursuit and Becky James collecting an unexpected silver in the keirin.

"It is going to pretty special tomorrow, said Dwyer. "The team pursuit women was an awesome performance. But Becky James is the most emotion final so far. It was not so long ago she was facing career-threatening injuries and it goes to show you should never give up on your dreams."

Val Mullaney: Fabulous - well done Jason. What a final it will be

Steve Calkin: Jason Kenny so sublime. All British ride off for gold and silver. Well done guys, Skinner & Kenny kings of track.

Wales international rugby union player George North, whose partner Becky James has just collected her keirin silver medal, has been talking to BBC One.

"I don't know much about cycling but fair play to her, she has worked so hard and we are all very proud," said North.

"Injuries are tough places at the best of times. It has taken Becky a lot of hard work and words can't describe how proud I am. I was so nervous, but I am a terrible spectator."

Victoria Pendleton
Olympic cycling gold medalist

Kenny v Skinner can only be described as a win-win situation.

Dmitriev closed the gap too soon, it was a rookie mistake.

That final won't be tonight, mind. You have to wait for 21:04 on Sunday for Kenny v Skinner.

Jason Kenny wins! He's not only won, he's thrashed Denis Dmitriev. Great Britain have two men in the final of the sprint. It will be a GB one-two, gold and silver guaranteed. 

The bell. Pace...

Kenny keeps an eye on the Russian. Cat and mouse. Both men would prefer to be at the back. Slowly, slowly...