Chris Henry made a try-scoring return for Ireland but their late comeback fell short as the Barbarians held on for a 22-21 win in wet conditions at Thomond Park.
The Ireland management tested out some promising youngsters and previously capped players who were returning from injury, and there were a number of positives to take into the upcoming Emerging Ireland tour and the Rugby World Cup warm-ups.
The Irish selection matched the Barbarians' three-try haul with the Ulster trio of Craig Gilroy, Chris Henry and Paddy Jackson all crossing the whitewash, while the uncapped Colm O'Shea and Tadhg Furlong and hooker Richardt Strauss were among the best performers on the night.
Furlong got the better of Roberto Tejerizo in the scrum, leading to the Argentinian prop being yellow carded in first half injury-time. He joined Jack McGrath in the sin-bin at that stage.
Ireland took a 7-5 lead into the break as Ian Madigan succeeded in converting Craig Gilroy's first quarter try which cancelled out Alex Cuthbert's opening score in the fifth minute.
Welsh winger Cuthbert went on to have a considerable say in the result as his second try in the 73rd minute, coupled with a classy Zane Kirchner effort and Jimmy Gopperth's seven-point kicking contribution, proved decisive for Robbie Deans' charges.
The Ireland XV, though sloppy at times, were resilient enough to carve out tries for Henry and Jackson in the closing quarter with Madigan converting both, including a terrific drop-kicked shot from out wide following Jackson's last-minute touchdown.
However, the outcome of tonight's non-cap international saw Ireland's poor record of results against the Barbarians continue, with the 2008 victory at Kingsholm being the only Irish success in six meetings with the world famous invitational club since 1996.
Shane Jennings captained a largely experienced Baa Baas squad in his last professional appearance on Irish soil, while Joe Schmidt's mix of youth and experience included five uncapped players – Furlong and O'Shea both started while Ben Marshall, Luke McGrath and Cian Kelleher were all involved off the bench.
The Baa Baas were first to threaten with Gerhard Vosloo breaking from a ruck to reach the Irish 22, and a rip in the tackle by retiring flanker Jennings led to David Smith haring after a kick on the left wing.
Lovely hands across the back-line then released Cuthbert for the opening try, Kirchner and Smith combining to send their back-three colleage over past Gilroy in the right corner with Gopperth missing the conversion in a tricky wind.
Ireland answered back with some good pressure exerted by the pack, using a run of penalties to launch their maul forward in the 22 and Furlong attacked Tejerizo at a couple of close-in scrums.
Good possession from the set piece five metres out saw Eoin Reddan link with the onrushing Gilroy who beat Ryu Koliniasi Holani's initial tackle and Jennings was unable to prevent the in-form Ulsterman from touching down.
Madigan converted and as the rain came down, the Ireland out-half was whistled up for a forward pass as he almost put the industrious Luke Marshall through for the hosts' second try.
Ireland began to dictate play via an increasing amount of possession in the second quarter, but the twin threats of Cuthbert and Smith kept the home side on their toes and the pair went close to setting up a score for their skipper Jennings.
On the half hour mark, the Baa Baas managed to disrupt a promising Irish maul and with TMO Dermot Moloney's input, referee Greg Garner yellow carded prop McGrath for a knee into the back of Georgian lock Konstantin Mikautadze at a ruck.
Centre O'Shea crashed through on a notable run close to half-time and although man-of-the-match Deon Fourie positioned himself well to win a relieving penalty for the Barbarians, they then had Tejerizo binned following his third scrum offence.
Kirchner provided the spark for the visitors just three minutes into the second period, though, as he skipped away from Madigan and Marshall and brilliantly gathered his own chip to score to the right of the posts.
Gopperth added the extras for a 12-7 scoreline and Dave Kearney, whom Kirchner had chipped past, did well to recover a dangerous situation after the Baa Baas countered from a Madigan mistake.
Rob Kearney also had to react quickly to collect a cross-field kick close to the Irish line, but the Barbarians deservedly added to their tally when Gopperth landed a close range penalty.
Loose passing from the visitors went unpunished when Joe Rokocoko got back to dot down for a 22-metre drop-out just ahead of Jackson, the liveliest of the Irish replacements.
George Smith's bone-crunching tackle ended Rob Herring's evening prematurely, yet the Irish forwards used their reliable maul to conjure up try number two. A patient drive ended with flanker Henry – back in green for the first time since his heart operation last November – muscling his way over. Madigan's conversion suddenly made it a one-point game.
Fourie and Smith were both prominent as the Barbarians used turnover ball to hammer away at the Irish line. Gopperth was held up near the right corner before Cuthbert completed his brace by flopping over from a close-in ruck.
Gopperth converted with the aid of the woodwork and that kick proved vital in the end as Jackson, who came on at out-half with Madigan moving to inside centre, made it over in the final minute from Luke McGrath's inviting pass. Madigan added an excellent conversion from near the left touchline, but it was his subsequent knock-on that allowed the Baa Baas to see out a hard-earned triumph.
TIME LINE: 5 minutes – Barbarians try: Alex Cuthbert – 0-5; conversion: missed by Jimmy Gopperth – 0-5; 16 mins – Ireland XV try: Craig Gilroy – 5-5; conversion: Ian Madigan – 7-5; 33 mins – Ireland XV yellow card: Jack McGrath; 40+2 mins – Barbarians yellow card: Roberto Tejerizo; Half-time – Ireland XV 7 Barbarians 5; 43 mins – Barbarians try: Zane Kirchner – 7-10; conversion: Jimmy Gopperth – 7-12; 55 mins – Barbarians penalty: Jimmy Gopperth – 7-15; 62 mins – Ireland XV try: Chris Henry – 12-15; conversion: Ian Madigan – 14-15; 73 mins – Barbarians try: Alex Cuthbert – 14-20; conversion: Jimmy Gopperth – 14-22; 80 mins – Ireland XV try: Paddy Jackson – 19-22; conversion: Ian Madigan – 21-22; Full-time – Ireland XV 21 Barbarians 22
Referee: Greg Garner (England)