Argentina stand between Ireland and a first Rugby World Cup semi-final appearance when they collide at the Millennium Stadium on Sunday.
Joe Schmidt's side have won their last five Tests with the Pumas but it is the South Americans who have held the edge at World Cups, winning two of the three meetings.
Ireland conceded just two tries during the pool stages and prevented both Italy and France from crossing the whitewash, but they come up against a prolific Argentina side that are the third-highest try-scorers in the tournament with 22.
Can Ireland cope without the loss of three key forwards, including skipper Paul O'Connell, and make history or will the Pumas progress to semi-finals for a second time? We look at five key talking points.
The Joe show goes on
Ireland's impressive victory over France was overshadowed by the World Cup-ending injuries to Paul O'Connell and Peter O'Mahony, as well as Sean O'Brien's lengthy appeal hearing, which was followed by a one-match suspension.
The loss of three pack leaders is a massive blow but Joe Schmidt is a coach who leaves no stone unturned. Since taking over as head coach the Kiwi has built a squad, not just a starting XV, and he will have instilled great confidence in the three forwards tasked with filling those sizeable voids on Sunday.
Captain Jamie Heaslip and Rory Best with be relied upon for experience in the pack, having both excelled in the role at provincial level, while O'Connell will return to the Ireland camp after surgery in London to ensure minds are focused on the Pumas.
The absence of O'Connell at lineouts will be missed but former Ireland international Shane Horgan is backing Devin Toner and Iain Henderson to stand up and be counted.
"I think Devin Toner is quite comfortable with calling lineouts," said Horgan of his former Leinster team-mate.
Clash of the hemispheres
Previous meetings between the World Cup quarter-finalists
"He has been Paul's apprentice now for quite a period of time so I don't think it's going to be a big issue. Iain Henderson has been picked alongside him and that doesn't hugely diminish the second row.
"You certainly lose some of Paul's traits but in Henderson you've got a guy with a huge future ahead of him. He's not the polished article but he's doing a lot of the right things at the moment."
Sexton starts
Schmidt insists there is no risk in throwing Jonny Sexton into Sunday's World Cup quarter-final with Pumas despite the fly-half's lingering groin injury.
Ireland have opted to gamble on throwing in their linchpin fly-half from the start in Cardiff, even though he has fought a fitness battle all week.
Sexton trudged out of Ireland's 24-9 victory over France at the Millennium Stadium after just 25 minutes last weekend, then immediately set about working to be ready for the last-eight encounter.
While Ireland have named their premier playmaker in their starting line-up, the 30-year-old will still most likely use all the available time until Sunday to ensure his groin issue has healed completely.
When asked if selecting Sexton carried any risk, Ireland head coach Schmidt insisted on Friday: "Not really. If he's fit he's fit.
"We don't tend to take too many risks with injured players. But there are always risks in everything you do.
"We've allowed Johnny to build his way back into the week. He had a fairly light start to the week but trained fully in the Millennium Stadium this morning.
"And we feel he's ready to go. It's been a very light training week, we've got a few guys carrying bumps and bruises.
Sexton starts for Ireland
Fly-half recovers from groin injury to face Pumas
"But we've got 48 hours more to freshen and hopefully be ready to go on Sunday."
Should Sexton suffer a late setback, Ian Madigan proved against France that he is a more than capable understudy. His assured performance against Les Bleus put to bed any doubts over whether he can compete at the highest level.
History favours Pumas
Despite having a superior win ratio over Argentina over the years, Ireland have struggled against the Pumas at World Cups.
In 1999, the first of their World Cup showdowns, Argentina stunned Ireland in Lens, scoring a try in the final 10 minutes to set up a 28-24 win in their quarter-final play-off.
Four years later Ireland edged a 16-15 win in Adelaide thanks to an Alan Quinlan try and two second-half penalties from Ronan O'Gara.
In 2007 Argentina famously topped their pool after beating France in the opening game and were resounding 30-15 winners over Ireland in their final pool fixture.
The record has buoyed Argentina coach Daniel Hourcade, who says his side's strike force will stamp their mark on the fourth World Cup meeting.
Pumas shuffle backs
Matias Moroni replaces Marcelo Bosch at centre
"We have the weapons we need to go against our rivals," said Hourcade.
"Ireland play in the northern hemisphere and play that way, but they've got some characteristics from the southern hemisphere, so they play a bit differently, very dynamic."
Best beware of Bajada
Argentina's unorthodox "Bajada" scrummaging method has caught several sides cold in the World Cup, the locks unusually binding on the props hips in a bid to pin all the pressure through the opposing hooker.
Ireland hooker Rory Best knows full well the Pumas will try to pin him in at the set-piece, but insisted Joe Schmidt's side have been hard at work devising strategies this week with scrum coach Greg Feek.
"We've got to make sure we have the tools to try to combat that," said the Ulsterman. "They are a quality scrum. Right through this tournament and the Rugby Championship they've performed very, very well.
"Traditionally everyone talks about Argentina and the scrum and it's probably only in the last couple of years they've got that back again.
"It's a big weapon for them. Ultimately we need to make sure that we're on the money, because they're a quality scrum.
"We know they're going to come after us because that's what they do no matter who they're playing.
"We need to be able to make sure that doesn't become a factor that makes us lose the game."
El Mago
In 2007 the Pumas' fortune was largely guided by the boot and magic of Juan Martin Hernandez.
The utility back, who starts in the No 12 jersey on Sunday, has fond memories of Argentina's win over Ireland in 2007.
He kicked three drop goals on the day, keeping the Irish at bay for the entirety of the game.
"It was very important, perhaps the most important to date," said Hernandez.
"I don't enjoy speaking of myself, but it was quite special because they had to score four tries against us.
"Besides, many of us played our club rugby in France back then, and we had family and friends sitting in the crowd.
"The match took place at Parc des Princes, only a block away from where I lived. There were many reasons that changed people's general opinion of me, or perhaps it was simply that they came to know me better."
Though not calling the shots for the backline this week, the Toulon star poses a huge threat to Schmidt's side.
Ireland: 15 Rob Kearney, 14 Tommy Bowe, 13 Keith Earls, 12 Robbie Henshaw, 11 Dave Kearney, 10 Jonathan Sexton, 9 Conor Murray; 1 Cian Healy, 2 Rory Best, 3 Mike Ross, 4 Devin Toner, 5 Iain Henderson, 6 Jordi Murphy, 7 Chris Henry, 8 Jamie Heaslip (c).
Replacements: 16 Richardt Strauss, 17 Jack McGrath, 18 Nathan White, 19 Donnacha Ryan, 20 Rhys Ruddock, 21 Eoin Reddan, 22 Ian Madigan, 23 Luke Fitzgerald.
Argentina: 15 Joaquin Tuculet, 14 Santiago Cordero, 13 Matias Moroni, 12 Juan Martin Hernandez, 11 Juan Imhoff, 10 Nicolas Sanchez, 9 Martin Landajo; 1 Marcos Ayerza, 2 Agustin Creevy (c), 3 Ramiro Herrera, 4 Guido Petti, 5 Tomas Lavanini, 6 Pablo Matera, 7 Juan Martin Fernandez Lobbe, 8 Leonardo Senatore.
Replacements: 16 Julian Montoya, 17 Lucas Noguera, 18 Juan Pablo Orlandi, 19 Matias Alemanno, 20 Facundo Isa, 21 Tomas Cubelli, 22 Jeronimo De La Fuente, 23 Lucas Gonzalez Amorosino.
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