The weeping grey skies in Paris currently reflect the sombre local mood. If there is one shimmering star this tournament can ill afford to lose it is Antoine Dupont, France’s captain and muse, and that doomsday scenario is now in play. Every Gallic effort will be made to patch up their national treasure but, right now, it feels like someone has walked into the Louvre and defaced the Mona Lisa.

It is also a reminder to every team at this World Cup just how quickly the bigger picture can change. For Ireland and South Africa, about to collide in a colossal pool game at the Stade de France, there are more direct implications. The losers may end up facing a Dupont-less France in a quarter-final, a different proposition to the full-fat version.

Related: Farrell’s Ireland gear up to meet South Africa’s might in heavyweight contest

Imagine Ireland going into Saturday’s game without Johnny Sexton or South Africa minus their talisman Siya Kolisi, both of which were possibilities at various stages. There are certain fixtures no one wants to miss and this is one of them, a showdown freighted with more significance than mere Pool B supremacy. These are the planet’s two top-ranked sides, fully loaded, with the world at their feet.

An Irish win, in particular, would send out a serious message. South Africa are not just the defending champions, they are a team who have already rapped out a few muscular statements over the past month. Their record demolition of New Zealand at Twickenham and the squeezing of Scotland have been duly noted in the Irish camp. “Of course, we’ll need physicality but we’ll probably need a good all-round performance in every area,” said Josh van der Flier, last year’s world player of the year.

The same is equally true for any side aspiring to beat Ireland nowadays. A big-game mindset is perhaps their key modern asset. Once upon a time Irish teams struggled to believe they could beat the best consistently. Slowly but surely, they have chipped away at that mental block. “We’ve had a Test series decider down in New Zealand in Wellington, we’ve had a grand slam decider, we’ve had a tough autumn series against some very tricky opposition,” stressed Paul O’Connell, the assistant coach who played in the era when Ireland often fell frustratingly short. “The boys have always found a way and figured it out. It’s a real strength of theirs.”

So is playing at pace, with sufficient precision and variation to make them an all-court threat. Does the Irish scrum terrify the world? No. Is their lineout the absolute best in show? Not always. But when it comes to organisation, making good decisions and calmly finishing what they start, there are few more cohesive teams or many with a better feel of where potential space might be hiding.

Normally that would be enough to guarantee another victory for a team who rarely take no for an answer. The snag is that South Africa are equally well organised and arguably even more motivated. Both squads have sought to broaden their games and minds in search of further improvement; if there are similarities it is no coincidence. Jacques Nienaber and Rassie Erasmus have both coached at Munster and taken plenty of inside knowledge back home with them, while a spell in Ireland is on the CVs of several Bok players, with no fewer than 14 of the matchday squad plying their trade overseas.

The margins, consequently, will be ridiculously slim: the width of a post, perhaps, or the thickness of a card. Sexton, for better or worse, will be at the heart of everything, his goal-kicking more reliable that Manie Libbok’s. Then again, the opposition will be pursuing him like hungry hyenas, fully aware of his importance as a tactical hub. “He is an amazing player and an important player for them,” murmured Kolisi this week. “You can see when he is there they are a completely different team.”

Which, as with France and Dupont, can be a double-edged sword. For Ireland to come through they will also need Bundee Aki, on the occasion of his 50th cap, to put them on the front foot. And for Van der Flier, Caelan Doris and Peter O’Mahony, playing in his 100th international including his solitary Test for the British & Irish Lions in 2019, to slow down opposition ball and deal with the multiple breakdown threats at the Boks’ disposal.

Because it is not just the Springboks’ power that has to be nullified. It almost suits South Africa to hide behind the cliché of one-dimensional giants when, actually, they are much more multi-layered. Three mobile ‘fetchers’ on the bench, the brilliant Kurt-Lee Arendse and Cheslin Kolbe on the wings; their 7-1 bench split does not tell the entire story. “I think they’ve developed their game since the last World Cup and developed their game a lot since last autumn, in particular,” confirmed O’Connell. “Our boys are under no doubt about how big a challenge it is.”

Listening to the remarkable Kolisi this week was also instructive, not least the level of detailed analysis undertaken by Nienaber and Erasmus. “It’s crazy … when we played Scotland I looked at this guy and I knew exactly how he was going to come and tackle me. And Rassie gets us as human beings. He reminds us exactly what we do and who we are doing it for. He also thinks about some of the mistakes he made when he played and he is not scared to share that. Whatever you are going through, he is always there.”

Always there. That was certainly how Scotland’s playmaker Finn Russell must have felt as, time after time, South Africa’s blitz defence cut off his supply lines and escape routes. Ronan O’Gara offered a few expert tips online this week, suggesting short passes, smart angles and inside balls were a better way to beat the Boks than spreading the ball wide. It may well be that Ireland, who have won four of the last six meetings between the sides including a 19-16 victory in Dublin last November, will take his advice. Either way, if they prevail this time it will be their finest World Cup achievement. So far, at least.

2023-09-22T18:00:15Z dg43tfdfdgfd