Hosts Brazil have drawn both of their matches against South Africa and Iraq 0-0, and going out of the group stage would be an unthinkable disaster in a home Olympics - just two years after they lost 7-1 to Germany in the World Cup semi-finals.

They know another draw might not be enough when they take on group leaders Denmark.

Earlier, China's Lyu Xiaojun broke his own world record in the snatch at the men's 77kg weightlifting.  

It's all over! Just six points in it as Australia take it to the wire but it's a win for the US. 

Luke Reddy
BBC Sport in Rio

Image source, .

It's worth remembering that Australia probably started this men's tournament as favourites. They hold the 2014 World Cup, the 2015 Hockey World League and 2016 Champions Trophy.

About a half full stadium again. I'm yet to see a full one in Deodoro this week. I'm going to head over to sit where I can see Aussies and Brits in close proximity, see if there's any Ashes-style sledging going on.

If Great Britain beat Australia then they're through to the quarter-finals - there's just the small matter of the 2014 World Cup champions to beat first. Having said that it's been a middling Olympics for the Australians so far - they've won just one of their three games.

Luke Reddy
BBC Sport in Rio

Image source, .

Coming to you from hockey under the lights.

This is a big one. A GB player told me last week that Australia are full on. He said you don't play them in a friendly because they only know one way and that's intensity, intensity, intensity.

As I enter the stadium I hear an Aussie fan say to his buddy: "Should be a good game mate."

The reply in a thick Australian accent: "Ah it's do or die mate."

Still all to play for in an absolute ding-dong, two minutes and change left.

Follow here. 

Rosalind Owen: I should be concerned about the Brazil footy team crisis but I'm totally distracted by the amazing sofa cushions in the #bbcrio2016, external studio  

Simon Mason
Ex-GB Olympic hockey player on BBC One

If either team loses this it makes it very difficult,  GB would have to beat Spain who are currently top of the group. It really is a very crucial game.

Australia are really struggling to score, which is the last thing you would think of from an Australian team. They get into the circle enough, they just haven't got the outcomes. 

And with that seamless link I can tell you that GB's men have just kicked off against Australia. It's goalless in the opening stages - follow here.

BBC Sport takes a look behind the scenes with the Great Britain men's hockey team during their Champions Trophy campaign.

Christopher Wood: Sorry but I'm going for a nap before that Phelps vs Lochte tussel in the pool later.

No need to apologise Chris. That race goes off at about 03:30 BST

Image source, Getty Images

Washout Wednesday. That's what everyone* was calling today in the tennis.

British number ones Andy Murray and Johanna Konta, plus 14-time Slam champ Rafa Nadal, were among those frustrated as rain prevented play at the Olympic Tennis Centre. 

Murray will now play Italy's Fabio Fognini about 17:00 BST on Thursday, with Konta and Wimbledon finalist Angelique Kerber following them on Centre Court.

Nadal starts against France's Gilles Simon at 15:00 BST.

*well we were

Reality has just about struck for Chris Mears after he and Jack Laugher won GB's first diving gold in 108 years. 

"I still can't believe it," he told BBC One. "Jack teared up instantly but I felt like I was going to wake up from a nap. But when I was on the podium it started to sink in and when I heard the national anthem I nearly went.  

"It is always tough when the pressure is on. You see the five rings and it puts it into reality about what you are about to do."

Georgia’s Varlam Liparteliani is inconsolable on the podium after being beaten by yuko in the men’s 90kg gold medal match by Japan’s Mashu Baker.