To say it wasn't pretty is a huge understatement and Ireland coach Eddie O'Sullivan will know that his side can play much better than this but he cannot fault their bravery, courage or commitment.
Ireland had to tough this one out and they did just that. It was trench warfare, body-on-the-line stuff and each and every one of this Irish side was prepared to do that. That they prevailed owed much to their own mental strength and a Puma side who offered little threat outside their pack, their backline ponderous and strangely unimaginative. Then, in the second half their line-out fell apart and with that gone Ireland just needed to be vigilant and disciplined in defence.
In the end there was just a point in it after Gonzalo Quesada had landed a 73rd minute penalty but the Ireland defence was superb in those closing stages as indeed it had been all day.
Ireland played with the wind in the opening half and for almost that entire period they ceded position and possession. Argentina sole ploy was to use their pack to bring them within scoring range and then rely on Quesada to notch the points. He opened the scoring in the seventh minute with a long range effort but Ireland claimed the only try of the game a little over ten minutes later. It came from a Puma line-out when Keith Wood hacked through the sloppy tap-down. He gathered well, broke clear and found Alan Quinlan in support for the Munsterman to cross on the left. Unfortunately, Quinlan damaged a shoulder in the process and was replaced by Eric Miller.
Quesada scrambled over a drop-goal in the 28th minute and four minutes later tagged on a penalty to leave his side trailing by one point at the break and with the freshening wind at their backs for the second half.
Quesada had an early chance to put his side in front when Paul O'Connell was penalised on his own 10 metre line but his effort went wide and O'Connell made amends immediately with a superb take from the restart to set up an Irish attack. Minutes after Ronan O'Gara had come on for Humphreys, Argentina edged in front with a massive Ignacio Corleto drop-goal but O'Gara restored the Irish advantage with his first penalty kick of the game in the 59th minute.
Crucially, O'Connell again won the restart and when O'Gara pushed the score out to 16-12 with a penalty five minutes later, O'Connell was again on hand to claim the kick-off.
It was all hands to the pump for the Irish from here on in and when Argentina were awarded a penalty with just seven minutes to go they opted to go for the posts rather than position, probably realising that their only chance of a score would come from Quesada's boot. He obliged to ensure a tense finish but Ireland held their nerve, their discipline and their composure to claim their rightful place in the semi.
Ireland: Girvan Dempsey; Shane Horgan, Brian O'Driscoll, Kevin Maggs, Denis Hickie; David Humphreys (O'Gara 55 min), Peter Stringer; Reggie Corrigan (Horan 56 min), Keith Wood capt, John Hayes; Malcolm O'Kelly, Paul O'Connell; Simon Easterby, Alan Quinlan (Miller 19 min), Victor Costello.
Argentina: Ignacio Corleto; Jose Maria Nunez Piossek, Jose Orengo, Felipe Contepomi, Diego Albanese; Gonzalo Quesada, Agustin Pichot capt; Roberto Grau, Federico Mendez, Mauricio Reggiardo; Ignacio Fernandez Lobbe, Rimas Alvarez; Lucas Ostiglia, Rolando Martin, Gonzalo Longo.