Replacements used: Hugo Kean (Blackrock College/Leinster) for Molony, Sean O'Connor (Rockwell College/Munster) for Claffey (both half-time), Jonny Guy (St. Andrew's College/Leinster) for Connors, David Duggan (St. Michael's College/Leinster) for Osborne, Calvin Nash (Crescent College Comprehensive/Munster) for McMahon (all 50 mins), Paul Kiernan (Presentation Brothers Cork/Munster) for Mulcahy (51), Greg Jones (St. Andrew's College/Leinster) for Deegan (55), Conor McIlmurray (Campbell College/Ulster) for Porter (56), Oisin O'Meara (St. Michael's College/Leinster) for Larmour (58), Elliot Boyd (Campbell College/Ulster) for O'Donnell, Jimmy O'Brien (Newbridge College/Leinster) for Stockdale (both 65).
Replacements: Jake Kerr (George Watson's College/Watsonians), Gary Robertson (Gala Academy/Gala), Callum Sheldon (Queen Elizabeth School/Newcastle Falcons), Lewis Wynne (St. Mungo's High School/Stirling County), Calum Hunter-Hill (Stewart's Melville College), Hugh Fraser (Merchiston Castle School), Max MacFarlane (Hutchesons' Grammar School), Robbie Nairn (George Watson's College/Currie).
Having being second best for much of the first half, Ireland scored three unanswered tries to record an encouraging victory as they build towards the upcoming FIRA/AER Under-18 European Championship in Poland.
A Jacob Stockdale try converted by Matthew Gilsenan gave Ireland a slender 7-6 half-time advantage, with Scotland's only points coming from two Rory Hutchinson penalties.
Replacement Calvin Nash, Gilsenan and Stockdale all touched down after the break as Noel McNamara's youngsters blew the Scots away with an impressive second half performance.
The Irish Under-18 Schools side had beaten the Ireland U-18 Clubs outfit 25-0 in December, while Scotland lost 28-6 to England earlier this month.
Those friendlies, including today's meeting, were part of both countries' preparations for the European Championship in Poznan from April 10 to 20.
Georgia will be Ireland's first opponents at Opalenica Stadium on Friday, April 11. Should they win that, they will play the winners of France and Italy at Plewiska Stadium on Tuesday, April 15.
Ireland won the tournament back in 2011 and have finished as runners-up on four occasions. At last year's competition, they came third overall after thumping Scotland 40-0.
But Scotland started this afternoon's game strongly at Coolmine RFC's Ashbrook ground. They nearly scored when Josh Laird charged down a kick in midfield, but the centre made too strong a connection with his punt forward and the ball went out of play.
After both sides missed early kicks at goal, the Scots took the lead through out-half Hutchinson's second penalty attempt in the eighth minute.
The hosts responded with the game's opening try on 14 minutes, Wallace High School centre Stockdale showing some neat footballing skills to dribble through and score on the right. Gilsenan converted to put Ireland 7-3 up.
A physical Scottish team kept up the heat on the home defence and after their powerful forwards drove back an Irish scrum, Hutchinson landed the resulting penalty.
That score on 27 minutes was the last of the opening half as Ireland went into the interval fortunate to be one point in front.
But they went eight points clear shortly after the restart with Scotland losing their loosehead prop Murray McCallum to a yellow card.
A clever midfield move - with Stockdale running a dummy line - saw Colm Mulcahy's well-timed pass release fll-back Jack Power on a break down the near touchline and he fed the ball back inside for Nash, who recently helped Crescent College Comprehensive retain the Munster Schools Senior Cup, to go over.
St. Michael's College out-half Gilsenan, who had missed a second penalty attempt just before Nash's try, added the extras.
Nash should have put a much-improved Ireland out of sight on 52 minutes, but the winger knocked on with the try-line at his mercy following a sweeping back-line move.
Just on the hour though try number three arrived when Gilsenan bundled over on the right to give the hosts a deserved 19-6 advantage.
Ireland continued their relentless assault on the Scottish line and from a huge overlap on the left, they scored a fourth try in the 65th minute when Gilsenan spun a long pass wide and Stockdale again crossed the whitewash.
Gilsenan took his personal tally to 11 points after his third conversion stretched the margin to 20 points, which was to be the final score of the match as Ireland's attentions now turn to Poland.
Referee: Tual Trainini (France)