The Scots, who fielded a strong squad after enduring an intensive training camp in Cumbria last week, produced a below-par performance in the opening 40 minutes.
Ruthless Tim Bergin notched a first-half hat-trick for the visitors within 31 minutes before Stuart Littler bundled over to give Ireland a well-deserved 22-0 lead at the break.
The sodden Meggetland pitch made life difficult for both sides and Ireland picked up where they left off after the re-start as a Callum Casey try was converted by Liam Finn to extend the lead to 28-0 three minutes into the second half.
But Scotland came to life after 59 minutes when Catalan Dragons star Ben Fisher dashed over from close range after a neat grubber kick, with Dave Scott adding the extra points.
The influential Fisher was again involved when Mitch Stringer touched down after a spell of pressure to make the score 28-12 after Scott once again slotted the conversion.
Liam Finn slotted another kick to consolidate the Irish lead as the Scottish defence conceded a cheap penalty which left the score 30-12.
The Scots kept fighting and it was a Fisher-inspired crossfield kick that forced an Irish fumble on the try-line and Edinburgh Eagles star Callum Cockburn pounced on the loose ball to reduce the deficit with Dave Scott converting to end it at 30-18.
Scotland manager Ollie Cruickshank said: “We were bitterly disappointed with our first-half performance, but the boys are looking to build upon the good work from the second half against Ireland and set a platform to build from for the World Cup next year.”