James Mortimer 30.May.2012getty
The victory has to be put into perspective as the Irish were without their Leinster contingent, who were rested after featuring in the RaboDirect Pro12 final.
The Baa-baas, coached by former All Black John Kirwan, were far more intense and ruled the collisions, while Felipe Contepomi won the game for the black and white hooped side with a penalty three minutes from time.
The Kingsholm crowd of 11,654 sided with the Barbarians, with local veteran Mike Tindall playing in front of his home crowd.
Another former Gloucester star in Iain Balshaw scored the opening try, before Ireland hit back with a good try to Craig Gilroy.
Benetton Treviso lock Cornelius van Zyl and English wing Paul Sackey also went over for the Barbarians in the first half, which gave them a 19-14 halftime lead.
Exciting wing prospect Simon Zebo went over to give the Irish back the lead, before the home crowd was sent into chaos when Tindall smashed the defensive line of Ireland to notch five points.
Keith Earls looked to have scored the matchwinner when he set up Gilroy for his second, before Contepomi took the Barbarians first penalty kick and gave the Barbarians the narrow victory.