France vs New Zealand got this Rugby World Cup off to a compelling start amid a febrile atmosphere, Wales vs Fiji provided the controversy and last-gasp drama before the Fijians then delivered the well-deserved upset against Australia. But it’s Ireland’s narrow, 13-8 win over South Africa that will go down as this tournament’s first true example of vintage, pure Test match rugby. And it was spell-binding.

The world No 1 and No 2 sides showed why they are ranked as such and, certainly now that France’s poster boy Antoine Dupont’s fractured cheekbone has become a national point of interest, it’s hard to argue that these two aren’t a cut above everyone else at the tournament.

If this contest was indeed a preview of the final and the teams are destined to meet again at the same Stade de France in 35 days’ time, then we’re in for a treat.

This was as physical and brutal a match as you will ever see, with 46 finely-tuned athletes leaving everything on the line but showing just as much skill and touch as brute force. Every inch mattered and the result came down to the very final play as the green Irish wall repelled a Springboks maul millimetres from the line before collapsing to the turf in relief at the sanctuary of the final whistle.

Their victory means Ireland will likely top Pool B and face New Zealand in the quarter-finals, although every Irish person will become Italian for the day next Friday as they root for the Azzurri to pull off the greatest World Cup shock in history against the All Blacks.

Ireland’s quarter-final jinx will provide a different kind of barrier – a hugely psychological one as they look to overcome the weight of history – but make no mistake, after this performance, there is no doubt they can win this World Cup.

They did what few teams have ever done, they matched and even surpassed South Africa physically as the Springboks’ battered bodies testified when they trudged off at the end. It was somehow fitting that even with seven forwards having come off the bench, the Springboks were unable to maul their way over the Ireland line at the death to snatch a draw and give themselves a shot at victory.

It was the ultimate statement of intent from Ireland. The greatest World Cup win in their history, as well as retaining the world No 1 ranking, was deserved reward.

The tone in Paris was set within 20 seconds of the opening whistle as Ronan Kelleher performed a crunching dump tackle on Damian Willemse that sent him flying backwards. The Springboks responded in kind as Garry Ringrose was spectacularly cleared out of a ruck and the marker had been laid down by both teams.

What followed for 80 minutes was a physicality not seen so far at this World Cup but was perhaps unsurprising as the top two ranked sides in the world fought for every inch in the carry, in the tackle and at the breakdown. It was mesmerising Test match rugby and if anyone ever suggests “the game has gone soft” as the authorities try to prioritise player welfare with regards to head contact and concussions, simply show them a video of this most intense of contests.

The brilliant Bundee Aki – already top of the pile in terms of carries, metres gained, defenders beaten, dominant tackles and linebreaks at this World Cup heading into the game – led the way again. He was Ireland’s go-to man on first-phase crash-ball carries where he would invariably get over the gain-line and fall forwards in contact. His stand-up tackle on Jesse Kriel just a metre from his own line midway through the first half epitomised the heart, and more importantly technique, that Ireland showed to repel their opponents. Caelan Doris snatched a turnover from an errant offload shortly after and the men in green escaped unscathed.

It was no surprise that Aki was at the heart of the game’s first try on 33 minutes as his 30-metre burst through the middle took the world No 1 side into the 22 and his carry out wide then put them back across that line after the Springbok defence had initially forced a retreat. After Johnny Sexton’s dart and sidestep got them within a metre, Jamison Gibson-Park spread the ball wide to James Lowe, who shipped it on to Mack Hasen for the run-in. The conversion gave them a 7-3 lead that lasted until the break.

If Aki was the leader through his actions, then Lowe led the way with words – visibly pumping up his teammates after every breakdown turnover or penalty won and celebrating passionately when he himself jackalled the ball away early on, to the delight of a roaring crowd.

And the mostly Irish crowd were a weapon for Andy Farrell’s men throughout as Lowe, Aki and Sexton all gestured to them to increase the noise after another key turnover in the 22 after Faf de Klerk’s monster penalty had struck the crossbar and been recovered by the chasing South Africans shortly after half-time. The atmosphere was almost as cauldron-like as it had been on the opening night in this same stadium when the hosts downed the All Blacks. Certainly, the raucous rendition of Zombie by The Cranberries after the full-time whistle echoed the way Freed From Desire rang round the Stade de France on that Friday evening.

The 7-1 forwards-to-backs split on the Springbok bench – a decision head coach Jacques Nienaber called a “calculated risk” – took the headlines during the build-up to the game and they only waited until the 47^th minute to start unleashing fresh reserves. The strategy received some immediate vindication as the new men helped the pack splinter an Irish scrum in the 22 before the ball was spread wide for Cheslin Kolbe to run over in the corner, although Ireland quickly retook the lead as they won a scrum penalty of their own down the other end and left Sexton’s boot to do the rest.

Jack Crowley added another late three-pointer after the skipper had departed as it was the Irish pack that finished the stronger, capping things off with the last-gasp maul defence that showed their guts and brought the glory.

Yet in some ways, it was the boot that would ultimately prove decisive. If there is one clear Achilles heel in this physical, well-drilled South Africa side it’s their kicking from the tee. De Klerk missed two long-range penalties, while fly half Manie Libbok was even more egregious in slicing wide a much simpler penalty and an eminently kickable conversion.

When the margins are so fine, that makes the difference and the decision to call up fly half Handre Pollard as an injury replacement for hooker Malcolm Marx is looking like shrewd move. That emergency glass may have to be smashed, at least as a bench option, once we reach the knockouts.

But that is a consideration for another day – on this evening at the Stade de France, the plaudits go to Ireland as they answered plenty of questions in the purest of Test matches. A rematch in just over a month’s time with the Webb Ellis Cup on the line? Yes please.