Wales (14) 31
Tries: Lennon (2), Webster, Williams (2), Roets Goals: White (3) Field goal: Briers.
Ireland (12) 30
Tries: Bergin, McNally (2), Boyle, Ambler. Goals: McNally (5).
Australia-based Mark Lennon scored twice for Wales at The Gnoll
Wales captain Lee Briers showed his experience as his late drop-goal was the difference as Iestyn Harris' team beat Ireland in the European Cup.
Mark Lennon and Rhys Williams scored twice as Wales set-up a winner-takes-all showdown in France next week for qualification to the 2011 Four Nations.
Huddersfield star Gregg McNally scored 18 points for Ireland - including a late try - but Wales held on in Neath.
Ian Webster and Christiaan Roets also touched down for Wales at The Gnoll.
The Welsh, who thrashed Scotland last week, won by the narrowest of margins against Ireland and will travel to Albi knowing victory against France would secure qualification to rugby league's 2011 Four Nations showpiece alongside England, Australia and New Zealand.
Wales coach Iestyn Harris said:
"We've used our get-out-of-jail card, if I'm honest.
"We were a little bit scratchy at times. Ireland came with a will to win and we did it tough at times.
"But if we keep improving and working on things that didn't go too well eventually we'll get there and hopefully that will be next week."
Wales: Andrew Gay, Mark Lennon, Gareth Thomas, Christiaan Roets, Rhys Williams, Lee Briers, Danny Jones, Jordan James, Lloyd White, Jacob Emmitt, Chris Beasley, Aled James, Ian Webster
Substitutes: Ben Flower, Ross Divorty, Jordan Ross, Neil Budworth.
Ireland: Greg McNally, Tim Bergin, James Haley, Jamie O'Callaghan, John Gillam, Scott Grix, Liam Finn, Ryan Boyle, Bob Beswick, Bret McDermott, Simon Finnigan, Luke Ambler, Matthew Fox
Substitutes: Sean Hesketh, Wayne Kerr, Matt Ashe, Joseph Taylor
Referee: Thierry Alibert (France)