TEST match rugby is won and lost by the narrowest of margins.

Nobody knows that more than Warren Gatland and his men.

Having kept the South Africans at bay with one of the best defensive shifts you are ever likely to see on a rugby field, they still ended up on the losing side and out of the Rugby World Cup.

One moment of magic combined with the slightest bit of indecision was all it took to allow Fourie Du Preez to snipe over as he took his side into a fourth semi final in six attempts.

Wales made the brighter start and once more were not able to capitalise on their early dominance.

Gethin Jenkins - who usually has one of the best sets of hands on the planet for a front rower - threw a horrible pass over Tyler Morgan's head with the tryline at his mercy.

That was less than three minutes into the game.

Score that - and Wales' gameplan changes completely.

Instead, they got turned around, marched into their own half and Handre Pollard slapped his team into a six-point lead.

From there on, Wales chipped away at the deficit until a sweet Dan Biggar drop goal on the stroke of half time gave his side the lead after his brilliance under the high ball had put them in front in the first quarter.

It was a case of get ahead and try to stay ahead, much in the way Jose Mourinho is criticised for in the world of football.

Difference being, the Chelsea manager usually wins, albeit not this season.

It's so difficult to swap from that mindset during a game.

To go in search of tries and not territory.

To look for space and not a penalty opportunity.

Once your brain tells your body the team is under the cosh, you can forget about it.

It appeared that's what happened to both teams as they seemed happier without the ball than with it.

The second quarter of the first half was a prime example of it with the Springboks kicking away every possession they had, forcing Wales to exit from their 22 - for 20 minutes.

With 90 kicks between the two sides, it was dull to watch, but mighty effective from South Africa.

Wales were never in danger of getting in range for Dan Biggar to slot three points.

The only time they managed it was from a 50m plus penalty which cannoned off the posts and landed in Schalk Burger's hands to be wrapped up by Jamie Roberts and co for a scrum.

Biggar slotted his drop goal shortly after and Wales went in a point to the good, which is when defensive mode kicked into over-drive.

It was special to watch without being remotely pretty.

Fifteen blokes willing to die for each other and their country on the rugby field.

Eight of the Welsh starting fifteen made it into double figures for tackles - Jamie Roberts made 13, Dan Biggar 10, Alun Wyn Jones made 19 while his second row partner Luke Charteris notched up 14 and the back row stats are frightening.

Sam Warburton made 17 tackles, Taulupe Faletau 18 and Dan Lydiate a frightening 24.

Paul James and Ken Owens managed 17 between them having come on as second half replacements.

The whole team made 197 tackles.

But will and desire can only get you so far in knockout rugby.

Having gifted South Africa with 15 penalty points, Wales would need a second bit of genius to go with Dan Biggar's and they didn't have it.

South Africa did in the form of Duane Vermeulen.

His captain told the media in the post-match press conference it's a move they've been working on and - if it's to be believed - Wales fell for it hook, line and sinker.

THAT SOUTH AFRICAN TRY

Shaun Edwards has tweaked the way his number nine defends at the scrum, probably due to the front five coming under constant pressure during the tournament tying up his back row.

Both Gareth Davies in the first half and Lloyd Williams for the try stood directly behind the scrum almost like a tail-gunner from the lineout.

If the scrum wheels one way or the other, the scrum half takes the place of the flanker stuck in the scrum, the free flanker takes over the number 8's responsibility and Faletau works as the flanker.

That's fine in principle, but if it moves outside of the channel usually covered by the back row - there's trouble.

The scrum wheeled, Justin Tipuric on the openside had 15 men between him and the ball, Willem Alberts held Sam Warburton in illegally - albeit smart - Vermeulen had a free run at Lloyd Williams and Alex Cuthbert.

He engaged both, flicked an offload to his captain, and won them the match.

ALEX CUTHBERT

Much has been made of Alex Cuthbert this World Cup.

Most of it justified but much of it way over the top.

For the try, if he's going to jam in on the number 8, he has to do it with gusto - that's the only criticism.

If he goes in hard on the ball, the offload doesn't come.

If he stays on his wing, he's got Fourie Du Preez covered, but he made the call and probably realised too late it was the wrong one.

There wouldn't have been anyone in front of him when he made the decision, which is probably the reason he's made the decision to go in for the tackle up high with Lloyd Williams clinging to Vermeulen's ankles.

To Cuthbert's credit, his defensive game has improved no end in the last 18 months.

Two defensive reads against Australia stopped certain tries.

But it's the disintegration of the rest of his game that's the worry.

He's never been blessed with a brain like Brian O'Driscoll or feet like Shane Williams.

He's big, he's fast, and therefore he fits the Warren Gatland mould.

His passing, kicking, catching and game awareness shortcomings didn't matter when he was running in tries like the two that helped demolish England 30-3 in 2013.

But now they have dried up, the light is shining brighter than Scotsman's bald head in Benidorm.

To put things in perspective, had Wales' injuries not reminiscent of a warzone, he wouldn't have been starting and was probably hard-pushed to make the bench.

He was what Warren Gatland had at his disposal.

He tried his best - probably too hard at times - but on the biggest stage it wasn't good enough.

It's not all doom and gloom for Wales.

Far from it.

DAN BIGGAR

Dan Biggar, despite not playing in the last two rounds, should be a shoo-in for the best number 10 in the competition.

He's been doing it for the Ospreys since 2007 and it a case of whether or not he could deliver the same level of performance after stepping up to international rugby.

It may well be those doubters he imagines being under his studs while he goes through his kicking routine.

Biggar is the youngest player to 100 appearances for the region in the Ospreys' history.

He first came onto the scene as a cocky kicking back with what seemed to be a chip on his wiry shoulders.

It took a while for some to realise the cockiness was not born of arrogance, but confidence, and the chip on his shoulder was his burning desire to win at any cost.

His meteoric rise has taken no Welsh fans by surprise and he's developed into the best fly-half in the world.

THE INJURY LIST

Biggar's World Cup ended in predictable fashion for what has become an unfortunate trend for Welsh players - off the field with an injury.

In the back division alone he's seen Jonathan Davies, Leigh Halfpenny and Rhys Webb all ruled out before a ball had been kicked and during the tournament watched Hallam Amos, Cory Allen, Scott Williams and Liam Williams all sent home.

In five games, Wales only fielded the same 10-12-13 combination twice and did not once manage to but the same backline out on the park.

Not one player or coach has blamed the injuries, but it has been clear to see the constant chopping and changing was a burden.

Players including Sam Warburton, Taulupe Faletau, Jamie Roberts and Dan Lydiate all admitted this one felt worse than the 2011 semi final defeat amid the captain's controversial red card.

But upon reflection, they will undoubtedly be proud of what they have managed to achieve in the face of such adversity during this campaign.

SOUTH AFRICA

But, an injury-ravaged Welsh squad are left with a giant dose of what could have been as they slipped to a 28th loss against the SANZAR nations in 30 matches.

South Africa were at their brutal best in the quarter final, typfied by flanker Schalk Burger. 

He topped the carries chart with a staggering 26 runs and was his side's top tackler with 16 to rightfully earn himself the man of the match award. 

Will they go on to win it - probably not.

Their pragmatic approach is reflective of Northern Hemisphere's grunt and grind approach, and with attacking rugby prevailing over the the defensive heroics, they'll be hard-pressed to get through their semi with New Zealand. 

Nevertheless, we're left the four Rugby Championship teams battling it out for a place in the final while the Northern Hemisphere teams are sat watching on the sofa.

NORTHERN HEMISPHERE v SOUTHERN HEMISPHERE

The north-south divide has been the elephant in the room for too long for it to be a problem people ignore.

It's just become one they can't understand.

The weather has been blamed given Southern Hemisphere teams tend to play on harder pitches in better conditions.

So why then when they come to the British Isles in the autumn, they come away with wins more often than not.

Super Rugby has been hailed as the holy grail of club rugby preparing them better than the European leagues and cups.

Both valid thesis, but it was telling Schalk Burger put the Wales game up with the most physical he's ever played.

This is one of the most confrontational players ever to have played the game.

In New Zealand, junior players do not play in age groups, they play in weight groups.

Anyone who's ever played school rugby can remember a game when the opposition had the policy of "pass it to the big kid".

If you did play school rugby and don't have that memory - that's because you were lucky enough to have the big kid on your side running in six tries as he carried an army of teenagers over the line with him.

Is rugby ingrained into players that early?

Is the bigger and stronger equals better approach part of our Northern Hemisphere DNA?

To look for the contact and not the space.

To win collisions and not beat the man.

To kick penalties and not score tries.

The only things we can say for certain is that the best four teams in the world are still in the Rugby World Cup.

They are all from the Southern Hemisphere.

So they must be doing something right.

PLAYER RATINGS

Gareth Anscombe: Employed by Warren Gatland as another ball-player in the backline but his kicking out of hand was poor and kept putting Wales under pressure. 4

Alex Cuthbert: One weaving run aside it was another night to forget for the out-of-sorts winger. 3

Tyler Morgan: Not able to show what he can do in attack but was magnificent in defence with one superb rip in tandem with Jamie Roberts. 7

Jamie Roberts: Another titanic display fuelled by pure emotion as he got through 14 massive carries and 13 tackles. 8

George North: If the 5m line was the tryline he'd have scored 12 this tournament. Some great runs showing glimmers of his best form. 7

Dan Biggar: Sublime piece of skill for Gareth Davies' try and a gladiator in defence as his stock on the fly-half market continues to grow at the top. 9

Gareth Davies: Found himself in the right place at the right time again for his fifth World Cup try in a tenacious display. 8

Gethin Jenkins: Blew try-scoring opportunity in opening phases with horrible pass but part of solid scrummaging display and one superb turnover. 6

Scott Baldwin: Quiet match in attack and over-threw his captain in vital second half lineout, but made 10 tackles without being extraordinary. 6

Samson Lee: Brought in to hold up the scrum - and did it. 7

Luke Charteris: Huge tackle count with 14 before being taken off but guilty of indiscipline that cost Wales points. 7

Alun Wyn Jones: Gave away three crucial penalties to feed Handre Pollards points but made up for it with 19 tackles and a handful of strong carries. 7

Dan Lydiate: Top tackler with 24 and all with a metal plate in his face. Justified his selection with another tree-felling masterclass. 8

Sam Warburton: Was a man possessed with 17 tackles and three crucial turnovers inside his own 22. 8

Taulupe Faletau: Fourteen runs and 18 tackles in another colossal performance. Up there with the best in the world. 8