Dan Sheehan then got over on the second wave of attack from a lineout in Argentina’s 22.
The gate to the bench was then thrown open in a box-ticking exercise rather than any need for assistance.
Two minutes into the second half, Sam Prendergast carved an opening for himself and had the gas to finish rather than look for support.
Ireland will enjoy a job well done, knowing an altogether tougher challenge is just around the corner.
Ireland ran in six tries against Argentina, with Hugo Keenan scoring three, in an emphatic Test win.
Those scores were split in sequence as Ireland found entry points that worked.
The first try came from a brilliant interchange that sent Keenan over.
If that comes to pass, Ireland will consider complacency their biggest enemy.
Before the hour mark Ireland had hit the Pumas for six.