And then there were eight! South Africa and Australia resume a long-standing rivalry when the two southern hemisphere heavyweights clash in Sunday's Rugby World Cup quarter-final at Wellington's Regional Stadium.
It's a mouth-watering encounter, but one that was never anticipated before the start of the tournament until Ireland split the road to the final into a southern and northern hemisphere highway after shocking the Wallabies (and perhaps everyone else for that matter) in their Pool C hit-out three weeks ago.
Australia's 15-6 defeat at the hands of the Irish effectively consigned them to a do-or-die battle against reigning champions South Africa, who finished the group stage of the competition unbeaten.
The South Africans booked their place in the play-offs after scraping through their opening game against Wales, but they looked far more impressive in the wins over Namibia, Fiji and Samoa.
Keeping things tight has not only given the Springboks those four wins out of four, but also the best defensive record from the pool phase - conceding just 24 points, ten fewer than the next stingiest defences of England, Ireland and Wales. Not conceding points is a good habit for teams to get into, as all previous World Cup winners have been among the top five defensive sides at the end of the group stages.
The Wallabies (48 points conceded) have had a more turbulent time in progressing to the knockouts - a win over Italy in the second half and a loss to Ireland, was followed by costly victories against the USA and Russia that saw two players sent home injured and several more in the casualty ward.
The Boks haven't had the pleasure of side-stepping injuries of their own and suffered a major blow to their campaign when losing in-form centre Frans Steyn and, most recently, veteran lock Bakkies Botha.
The injury-hit outfits must now pick themselves up for one of the most eagerly awaited World Cup spectacles of the weekend, which after 80 minutes will decide who stays on to fight another day and who goes home.
The Springboks have lost five of the last six Tests against their Tri-Nations counterparts, but as shown many times on the World Cup stage - previous results mean absolutely nothing when there's a semi-final at stake. And on neutral ground, this game is certainly anyone's for the taking.
Both teams have been crowned world champions twice, and are gunning for a record three championship titles.
The last time these sides met at a World Cup - in 1999 - South Africa were defending their crown only to be knocked out in the semi-finals by Australia (who went on to lift the Webb Ellis Cup for a second time - a record back then).
Fast forward 12 years later, and again we find ourselves in a similar scenario: defending champs South Africa versus the Wallabies in a knockout match, however this time a place in the last four will be up for grabs.
History sure has a funny way of repeating itself, but not unless the wise old owls of the Springbok team have anything to say about it when they tackle the baby-faced Wallabies who, with the youngest squad in the tournament, will take on the most experienced Test team of all-time.
Only six members of Australia's matchday 22 played in the 2007 quarter-final exit to England in Marseille, whilst the rest of current squad played no part in the tournament four years ago.
South Africa's selection includes eight players who started in the 2007 Rugby World Cup Final as well as three players who were part of the squad. Only Pat Lambie, Morne Steyn and Heinrich BrÃ¼ssow of the starting team were not involved in 2007, while Pierre Spies was originally selected but had to withdraw due to illness.
But whilst South Africa can boast more World Cup caps on their CV, a full-strength Wallabies outfit is always a dangerous one and the return of David Pocock, Stephen Moore and Digby Ioane - three influential players that missed the Ireland game - will be a welcome boost for Australia.
The Wallabies know their shock loss to Ireland has left them walking the finals tightrope in the horror southern hemisphere side of the draw, but the Tri-Nations champions will draw much confidence from the return of the above mentioned trio.
It also means that with a full-strength line-up back on deck for the Australians, coach Robbie Deans must accept there can be no excuses for a disastrous World Cup quarter-final exit.
Speaking of coaches, Peter de Villiers faces the biggest challenge of his four-year career as boss of the Springboks. The thin line between success and failure has never been as apparent as now.
"Australia won't be easy, but they will be easier," said De Villiers.
"There are two reasons for this. Firstly they won't be as physical as Samoa, but they will try to be. It is just Samoa who can be as physical as that, because it's part of its nature.
"Secondly, we understand Australia and we know what they do. We've been playing them for years, and they're not likely to change anything this coming week. For them it will be easier and for us it will be easier."
The Boks have made no secret that their setpieces will be the basis for their attack, and armed with a stingy scramble defence, they will feel assured that they have the firepower to beat the Wallabies.
However, whilst the men in green and gold pack a punch up front, the Wallabies can deal a knock-out blow with their ruthless backs who ran South Africa ragged in Sydney two months ago - albeit against a second-string Bok team.
But whether it's up front or in the backs, one thing's for sure is that there will only be few opportunities to win this match come kick-off on Sunday and the team that is up for it and ready to take those chances will be the one that will be staying.
Ones to watch:
For South Africa: The big talking point leading into this quarter-final was the loss of Frans Steyn and how South Africa's back-line will cope without his physical presence on attack and defence. Jean de Villiers was the first-choice centre before his injury against Wales, and now returns to the Bok midfield with some mighty big boots to fill. In the forwards, the injury to Bakkies Botha could be a blessing in disguise for SA as it keeps big Danie Rossouw - arguably the Springboks' player of the tournament - in the starting line-up.
For Australia: In the backs, keep an eye out for tackle-busting wing Digby Ioane who returns to the fray after recovering from a broken thumb. With the wet weather that has been hanging over Wellington this week set to clear by Sunday, the Wallabies will be intent of getting the ball wide to their strike runner more often than not. Up front, Stephen Moore will make sure the Aussie scrum (that took a battering against the Irish), only goes one way when the two front rows lock horns in the New Zealand capital.
Head to head: Heinrich BrÃ¼ssow v