A quickfire half century from Neil Rock saw Ireland's young cricketers beat the MCC in a last over thriller at Belmont.
Chasing 228 for victory in their 40-over match, Oliver Metcalfe (43) and Marcus Poskitt (25) gave the Irish the perfect platform with an opening stand of 72 before both departed in quick succession.
Reece Malone hit 28, while Andrew Vincent (32) then was joined by Irish skipper Rock and the pair added a 72 for the fourth wicket.
Rock's half century took just 36 balls and included 5 fours and 2 sixes.
A late wobble saw Ireland needing 8 off the last over, but Gavin Hoey hit a four and took a single, before Varun Chopra thumped a six to seal the three wicket win with three balls to spare.
The Clontarf pair of Joe Morrissey (41) and David Delany (37) were among the runs for MCC as they made 227 for 8.
Cian Nulty (2-37) was the best of the Irish attack, while there were also wickets for Gavin Hoey, Kyle Magee and Varun Chopra.
MCC Tour of Ireland
At Belmont, Ireland U19's beat MCC by three wickets
MCC 227-8 (40 overs; F Simon 48, J Morrissey 41, D Delany 37; C Nulty 2-37)
Ireland U19 231-7 (39.3 overs; N Rock 52, O Metcalfe 43, A Vincent 32, R Malone 28, M Poskitt 25)