Australia and Wales meet in Pool A's final big showdown this weekend knowing that their respective places in the knockout stages have already been secured.
With tournament hosts England now disposed of, it is a straight shootout between the Red Dragons and the Wallabies for top spot in the 'Group of Death'.
Australia
That is not to say Saturday evening's clash has little riding on it, though, as the two teams know full well that a meeting with fellow heavyweights South Africa awaits the losing side.
The Springboks topped their own pool to secure what turned out to be a straightforward enough path through to the quarter-finals following the competition's shock result in the opening round of fixtures.
That defeat against Japan has simply made the two-time winners all the more determined to succeed, so Australia will need to get the better of Wales if they are to avoid a showdown with their fellow favourites.
Michael Cheika has acknowledged that his side will essentially be the visitors for this Pool A decider, despite the neutral choice of venue at Rugby HQ, with thousands of Welsh supporters expected to make the trip across the Severn Bridge once again.
It is a ground that carries fond memories for both, particularly over the past fortnight, but only one can come out on top on this occasion.
Australia have improved progressively as the tournament has gone on, building on their three-try win over Fiji by comfortably dispatching Uruguay and proving far too high a hurdle for England to overcome last time out.
That has only helped to strengthen the pre-World Cup thoughts of many, who backed the Southern Hemisphere giants to go all the way and lift the Webb Ellis Cup, 16 years after last doing so in Cardiff.
Australia's hugely impressive hold over Wales in recent years certainly stands them in good stead to take a giant leap towards another final, but they know that a performance to match that of last weekend will be needed if they are to claim top spot.
Recent form: WLWWWW
Wales
If last week's meeting with Fiji presented a potential banana skin for Wales's hopes of progression, then there was certainly no mistaking the task they faced either side of that match.
The famous victory over England at Twickenham, a result that will no doubt be re-watched by Red Dragons supporters for years to come, provided the footing for Warren Gatland's men to push on and confirm their spot in the quarters.
Many bookies had Wales to fall at the pool stage, more because of the level of their opponents than their own capabilities, but Gatland has shown yet again why he is considered among the world's greatest coaches.
There is a sense that momentum is swinging his side's way, too, particularly in terms of fitness news as he has essentially a full squad to choose from for this latest 'must-win showdown'.
Gatland himself has admitted that another step-up in quality will be required if Wales are to make it four wins from four, however, with "momentum" very much the key word now being used in the dressing room.
Wales have never previously won four World Cup games in succession, so more history could be made in the English capital, while they have not gone through an entire group phase without defeat since 1987.
Perhaps tellingly, though, only two players - Alun Wyn Jones and Jamie Roberts - can boast a victory over Australia on their CV. That anomaly in the long list of past results in this meeting came seven years ago now, which certainly does not bode all that well for the Welsh.
Yet with so little pressure on their shoulders, and an army of supporters behind them, this could be the Dragons' time to roar once more on enemy territory as they aim to send a message out to the watching world.
Recent form: LWWWWW
Team News
Wales have made six changes to their starting XV from last time out, with Gareth Anscombe coming in at full-back and fit-again Liam Williams returning on the left wing.
George North has also been switched to the centre for this weekend's clash in place of Tyler Morgan, but Gatland has opted not to use Dan Lydiate who he claims is still feeling sore.
Australia delayed the announcement of their team, having been forced to hold some late fitness tests. It is good news for the Aussies, however, as Israel Folau has been declared fit to start.
Injured wing Rob Horne does miss out, meanwhile, and suspended flanker Michael Hooper will also play no part, meaning that Sean McMahon and Drew Mitchell both come into the fold.
Australia starting lineup:
Folau, Ashley-Cooper, Kuridrani, Giteau, Mitchell, Foley, Genia, Sio, Moore, Kepu, Douglas, Mumm, Fardy, McMahon, Pocock
Wales starting lineup:
James, Baldwin, Lee; Charteris, Wyn Jones; Warburton, Tipuric; Faletau; Davies, Biggar, Liam Williams, Roberts, North, Cuthbert, Anscombe
Head To Head
These two sides have played 38 previous Tests, with Australia leading things 27-10 overall. The other match in that sequence ended in a 29-29 draw at the Millennium Stadium in 2006.
They have also met at five of the previous seven World Cups, including in each of the last two where Oz once more tightened their grip on things by winning four of those games.
In fact, this will become the joint-most common encounter at a World Cup when the heavyweights run out for a sixth time on Saturday evening.
Australia have not lost any of their last 10 meetings with Wales in a run stretching back some seven years now, with the European outfit's last triumph coming in Cardiff during the early days of Gatland's reign.
We say: Australia 30-26 Wales
A tight match can be expected at Twickenham under the floodlights, but it is Australia who have dominated this fixture down the years. That is likely to continue at the weekend as the Wallabies maintain their winning run at the expense of their Pool A opponents.
