Someone's let a bugler in. It sounds like the third day of a Test match down under.

Half a chance for Greece again, as Sokratis Papastathopoulos nods wide from a corner. Greece may well have the advantage from dead balls. Plenty of height and strength. And letters.

Former Blackburn Rovers striker Jason Roberts
BBC Radio 5 live

"The backbone of Costa Rica's solid defence is their 5-4-1 formation, which switches to a 4-3-3. The wing-backs are very ambitious going forward but are also very defensive minded when they need to be.

"A couple of sides have come up against it and tactically not known what to do. But today Costa Rica will have to be careful about the way they commit men forward. It's different to playing Uruguay or Italy.

"Costa Rica are dictating this game. But when Greece need to attack they can be very good, as they showed against Ivory Coast, and are also dangerous from set pieces."

Image source, Getty Images

Giorgos Samaras is the Greek island furthest forward, and he chests down a long ball beautifully and looks to break in - but the offside flag was up. He needs support up top.

Greece then have another effort, and again it's Lazaros Christodoulopoulos. Not doing the commentators any favours...

That is a nice flowing move from Costa Rica.

Joel Campbell drops deep to pick the ball up, he is fouled by referee Ben Williams waves him on, Bryan Ruiz plays it out to Christian Bolanos on his left shoulder but the Copenhagen man can't keep his shot down and drills it over the top.

The crowd roar their approval to the Ticos, who have settled well.

Image source, Reuters

A terrible pass from Andreas Samaris almost plays Costa Rica in on goal but Bryan Ruiz is crowded out when perhaps he could have got the shot away earlier. Both sides looking sloppy on the ball early doors.

Former Blackburn Rovers striker Jason Roberts
BBC Radio 5 live

Image source, Reuters

"My last game playing for Grenada was a 0-0 draw against Costa Rica. They took us up into the hills somewhere and I seem to remember being kicked all over the pitch on AstroTurf. But today I am of course impartial."

The pocket of Greece fans are making some excellent noise in these opening exchanges, but the majority of the crowd remain behind Costa Rica and Cristian Gamboa gets the ground rocking with a low skidding shot wide of the far post.

Former Blackburn Rovers striker Jason Roberts
BBC Radio 5 live

"For both these nations it is a huge occasion but in different ways. Costa Rica have never been to the quarter-final. For Greece I've heard that because of the issues back home they are going to donate their bonuses back to the Greek FA.

"Both have a lot to play for. I was so impressed with the way Costa Rica's midfield contained Andrea Pirlo in their win over Italy. How Greece are able to keep up with the pace of Yeltsin Tejeda and Celso Borges will be key to who wins this midfield battle."

You can listen to BBC Radio 5 live's commentary by clicking on the Live Coverage tab at the top of this page.

Greece with the first shot of the game, as Lazaros Christodoulopoulos fires well over the top. If you wanted Lazaros Christodoulopoulos' name on the back of your Bologna shirt, it would cost you approximately 300Euro to have it stitched on.

False start! Costa Rica jump the gun on the kick-off, but we are under way at the second attempt.

The Greek anthem gets jeered as it is announced. From first impressions it seems that the neutrals are siding with Costa Rica.

Tony Munky:, external I reckon this one has penalties all over it, hopefully Costa Rica to win.

Jonathan Northall:, external I'm going for a 1-0 win for Costa Rica-ca-ca.

Eyobel Gomini:, external Costa Rica to thrash Greece 4-0, Joel Campbell to grab a hat-trick!

Here we go then! The boys are on the park, it's anthem time.

We've got an Australian ref tonight, Ben Williams, and he may be the most casual ref I've heard at a major game.

After pulling Greece captain Giorgos Karagounis to one side, this was his opener:

"Ah look mate, if it goes to extra-time, we'll keep the boys on the park. You can all have a drink and we'll turn it around, alright? You know the drill buddy."

The Greeks are incredibly vocal in the tunnel. Pumped.

Arnold Kanyangonda:, external Greece may well be the least enterprising, least entertaining, most uninspiring team to ever make the knockout stages.

Luke:, external Eagerly awaiting another master-class from Joel Campbell. Not many players are born for the Premier League.

Less than 15 minutes away from kick-off then and I've already seen one child asleep in the stands. Come on, let's get up for this one.

It's going to be a World Cup classic. 4-4 AET.

Image source, AFP

We've been asking if Greece winning Euro 2004 is the biggest upset in a major tournament? Can anyone top it? How far can Greece or Costa Rica go this time? What's the key to victory in Recife?

Aaserhna:, external Nigeria coming from behind to beat Brazil with a golden goal at the Atlanta 1996 Olympics qualifies as one of best major upsets.

Image source, AP

This evening will be another chance for Arsenal fans to get a glimpse of one of their own as Costa Rica striker Joel Campbell aims to shine.

Campbell was signed by Arsenal in 2011 but has never played a game for the club, though Arsene Wenger has reportedly said that he wants Campbell involved in the new season.

"As a youngster, he would juggle empty cans on the street," says our reporter Ben Smith.

"On one such occasion he was spotted by then Costa Rica manager Ricardo La Volpe. The national side were playing friendlies close by and, while his friends bought tickets to go to the games, Campbell told them all he wanted to go, but as a player. A few weeks later, La Volpe called him up to the Costa Rica national team."

Jon, Brentwood: The three quarter-finalists through so far are all group winners. I'm going for Costa Rica to make it four.

BBC Radio 5 live

BBC Radio 5 live will have full coverage of the 21:00 BST kick-off between Costa Rica and Greece, with Alistair Bruce-Ball and Jason Roberts providing the commentary.

Alternatively you can listen to BBC Radio 5 live's commentary by clicking on the Live Coverage tab at the top of this page.

Later you can watch highlights of Costa Rica v Greece and the earlier match between Netherlands and Mexico on Match of the Day from 01:05 on BBC One.

How to follow the World Cup across BBC TV, radio and online.