England's Simon Dyson clinched his fifth European Tour title with a one-stroke win ahead of Richard Green.
Australian left-hander Green had a long putt to snatch the championship on the final hole but ended up taking a bogey to hand victory to Dyson on 15 under.
Scotland's Stephen Gallacher holed a monster birdie putt on the last to claim third place on his own.
David Howell, tied for the lead overnight with Dyson and Green, fell away with a 73 on the Killarney course.
Peter Lawrie was Ireland's best finisher on nine under while Portstewart amateur Paul Cutler completed a fine week on five under.
Dyson had just three bogeys all week and his win earns him a place in this week's Bridgestone Invitational in Ohio.
"I will have to phone my travel agent now," said Dyson on his changed plans.
"Ireland is a place I really enjoy coming to but I have never really played well in this tournament."
Defending champion Ross Fisher finished with a two-over round of 73 to end up nine behind the winner.
Fisher could be excused for having his mind elsewhere. His baby son Harry, with him in Ireland, was taken to hospital on Saturday after falling ill and was kept in overnight for observation.
Northern Ireland's big hopes, Graeme McDowell (-4) and Rory McIlroy (-3) failed to mount a serious challenge for the title.