Cardiff Blues winger Alex Cuthbert scored two tries as the Barbarians beat Ireland by one point for a third time in recent years.
The invitational side’s other try at Thomond Park came from Leinster’s South African back Zane Kirchner.
The three Irish tries came from Ulster players Craig Gilroy, Chris Henry and replacement Paddy Jackson.
Back row Henry, 30, was playing his first match in an Ireland shirt since undergoing heart surgery last year.
Jackson’s try came in the final minute with Ian Madigan drop-kicking the conversion from the touchline.
It meant another one-point game as the Barbarians had beaten Ireland 29-28 three years ago and 31-30 in 2000.
The first half did not witness much of the flamboyant, open and attacking play with which the Barbarians are associated.
But it was a competitive affair on a damp, uninviting night in Limerick.
The Baa-Baas struck the opening blow when a period of early pressure was rewarded with Welsh winger Cuthbert getting over on the right inside five minutes.
Fly-half Gopperth, leaving Leinster after two years to join Wasps, was off target with the conversion.
Ireland, with players eager to impress coach Joe Schmidt ahead of the World Cup warm-up fixtures against Wales, Scotland and England, summoned a speedy response with Gilroy scoring the equalising try in the 16th minute.
The Ulster winger blitzed on to Eoin Reddan’s inside pass for the score and the conversion, landed by Madigan, edged the Irish into a 7-5 advantage which remained until half-time.
Both sides had a man sent to the sin-bin in the opening half. Ireland front row Jack McGrath showed ill-discipline as he went in with the knee and just before the interval Argentine prop Roberto Tejerizo was adjudged to have come out of the scrum.
The Barbarians regained the lead early in the second half with a fine, flowing attack capped superbly by full-back Kirchner.
The ball was worked out to the right and Kirchner cut in, chipped over opposing winger Dave Kearney, collected on the run and dived over to score.
Gopperth converted and added a penalty to give the Baa-Baas a 15-7 advantage.
Ireland hit back through a try scored by open-side Henry, who suffered a mini-stroke in November.
The Ulster back row was on the end of a dominant rolling maul after a line-out to revive Ireland in the 62nd minute, with Madigan converting again to leave them just one point behind.
However, the Barbarians extended their fine record against Irish teams as Cardiff Blues wing Cuthbert snapped up his second try.
It followed a period of pressure during which the invitational side had several charges at the line, and Cuthbert just got the ball over before Gopperth converted via the inside of the far post.
Jackson’s score gave Ireland brief hope but it came too late to deny the Baa-Baas.
Barbarians: Kirchner, Cuthbert ,Rokocoko, Olivier, D Smith, Gopperth, Pienaar; Tejerizo, Fourie, Jones, Capo Ortega, Mikautadze, Jennings, Vosloo, Holani (Taumoepeau 45), Taumoepeau (G Smith 50).
Not used: Ward, Diaz, Whitelock, Cubelli, Pisi, Aplon.
Ireland: R Kearney, D Kearney, O’Shea (Kelleher 74), L Marshall (Jackson 50), Gilroy, Madigan, Reddan (L McGrath 62), J McGrath, Strauss (Herring 54), Furlong (Ross 62), Toner, Tuohy (B Marshall 62), Diack (Bent 40), Henry, Heaslip.
Not used: Murphy.
