Yesterday, their forwards laid the foundation by dominating up front with the Scots looking to move the ball away from contact and utilise their backs as much as possible.
Ireland's preparations were disrupted when captain Stephen Keogh was forced to withdraw before the kick-off with a back injury. However thery took the lead with a penalty after two minutes from out-half Michael Rainey and he landed a second, five minutes later before the Scots responded with a try from Nikki Walker, the winger capped at full international level.
Alistair Warnock missed the easy conversion but added a penalty just after Rainey had kicked his third.
A minute before the break, the Irish scored a crucial try when the Scots were reduced to 14 with the sin-binning of Alistair Hogg. From a scrum close to the line, number eight, Ciaran Potts dived over to leave his side 14-8 up at the break.
After a scoreless third quarter in which the Irish defence was severely tested, The Irish made the game safe when O'Brien pouinced on a loose ball and scorched away for the try that sealed the outcome.
Ireland. 15. Peter O'Brien - UCC14. Keith Matthews - UL Bohemians13. Barry Murphy - UL Bohemians12. Glen Telford - Instonians11. John Hearty - Blackrock College10. Michael Rainey - Glasgow Hawks capt 9. Fiach O'Loughlin - Shannon8. Ciaran Potts - St. Mary's7. Niall Ronan - Lansdowne