Decimated by injuries and missing their core leadership, slight favourites Ireland looked down and out after just 14 minutes when they fell 17-0 behind.
They did, however, managed to fight back in the second half and give themselves a chance to win it.
But ultimately, they couldn’t maintain anywhere near enough pressure as the Pumas’ power and pace paid off dividends.
43-20 the final score.
Bravehearts battle but fall short
Scotland were less than a minute from causing a massive upset but went down 35-34 to Australia in a pulsating match at Twickenham.
The Scots were on the verge of victory when Mark Bennett’s converted interception try put them 34-32 up with seven minutes remaining.
But Bernard Foley’s last minute penalty sent the Wallabies through to complete a clean sweep for the southern hemisphere in the quarter final victories.
The Wallabies will now face Argentina while holders New Zealand play South Africa.