Ireland began to come more into the game and finished the half strongly with Alan Quinlan's block down of Todeschini's attempted clearance almost leading to their opening try before Bryan Young forced his way over the Puma line but was held up.
The half ended with the Irish pounding the Puma line and after a succession of Ireland scrums they opted to kick a penalty that Staunton blasted wide from right of the posts.
Three minutes into injury time after Ireland had turned over ball, Shane Jennings was pinged for blatantly coming in from the side and Todeschini's kick extended the home side's lead.
Ireland: G Murphy; B Carney, B Murphy, G Duffy, R Kearney; J Staunton, E Reddan; B Young, F Sheahan, S Best capt; L Cullen, M O'Driscoll; A Quinlan, S Jennings, S Ferris.
Argentina: F Serra; T De Velda, H Senillosa, M Contepomi, F Leonelli; F Todeschini, N Fernandez Miranda; M Ayerza, P Gamborini, S Gonzalez; E Lozada, R Alvarez; M Durand, J Fernandez Lobbe, J Manuel Leguizamon.