Ireland made a strong start, going in front through Johnny Sexton’s sixth-minute penalty, but Wales began to give as good they got during a thunderous opening punctuated by some bone-crunching tackles, and they conjured a magnificent 20th-minute try.
Rhys Webb broke clear following a lineout, then linked with Scott Williams before firing out a long pass to Leigh Halfpenny, who sent North powering over for his 29th Wales touchdown.
Although Halfpenny sent the conversion attempt wide, the home side led 5-3 after a pulsating opening quarter.
Paddy Jackson kicked Ireland in front just before Sexton returned following a nine-minute absence, but Wales finished the first-half on top and Halfpenny kiched them ahead as Sexton’s eventful night continued when he was yellow-carded for killing possession on Ireland’s line following a tackle on centre Jonathan Davies, who almost scored when Webb’s clever kick found Liam Williams, before Halfpenny’s pass sent Davies to within touching distance.
Halfpenny’s simple penalty made it 8-6, ending a gripping 40 minutes that enthralled a capacity 74,000 crowd, and Wales increased their lead four minutes into the second period whenthe forwards drove relentlessly before Webb sent an unmarked North over again.
Sexton cut the gap with his second penalty, and Ireland put together a sustained spell of pressure but Wales prevailed and Roberts marked his 90th cap by finishing them off.
The result means England can secure the Six Nations title for a second successive season if they beat Scotland at Twickenham today. A draw or win for Scotland could lift them above Ireland into fourth place in the world rankings.