Wales were 23-3 down at the break after tries from Simon Zebo and Cian Healy and the boot of Jonny Sexton shocked the Millennium Stadium.
Brian O’Driscoll’s early second half score pushed Ireland further clear but Alex Cuthbert and Leigh Halfpenny both went over as Wales roared back into contention during a thrilling second half.
And although Rob Howley’s side pounded the Irish line in the last half an hour and saw replacement Craig Mitchell add a third try, their first half deficit proved too much to overcome.
Here is how five key battles decided the outcome of the Six Nations opener at the Millennium Stadium.
Toby Faletau vs. Jamie Heaslip
The Irish captain saw his side get off to a winning start but did not have it all his own way at the breakdown. Like many of the Welsh team, Faletau grew into the game in the second half and was effective in the loose as Wales started to throw the ball around. One break down the wing saw the Dragons man at his best and he was powerful in the contact area, topping Wales’ ball carries and tackles made statistics. He also came close to scoring in the second half but it was Heaslip who left the happier man.
Dan Biggar vs. Jonny Sexton
Leinster man Sexton was at his imperious best in the first half as he guided Ireland into the lead. An early chip through pinned Wales back inside their own half and the rest of the half couldn’t have gone much better for him. Biggar saw his kick charged down in the build-up to Healy’s score but stood up to be counted during the second half as Wales grew into the game. The Ospreys man prompted Wales throughout as they had the better of the last 40.
Leigh Halfpenny vs. Rob Kearney
Halfpenny was Wales’ main man during the autumn and the full back was at it again during the Six Nations opener. Going up against his main rival for the Lions number 15 shirt this summer, Halfpenny was rock solid in defence and superbly finished the one chance that came his way. An early aerial challenge with his opposite number went the way of the Cardiff Blues man and although Wales struggled in the first period, Halfpenny mopped up a number of kicks diligently. And as Wales stormed back in the second half, his brilliant finish in the right corner saw Wales cross for their second try. After outshining Kearney, surely the Wales man must be nailed on for a Lions starting spot?
Mike Phillips vs. Conor Murray
A slow start saw Phillips struggle to release what was a hugely dangerous Welsh back line. Once provided with quicker ball, his distribution saw the likes of Cuthbert and North test the Irish defence. Murray was sent to the bin in the second half before Phillips was replaced by the energetic Lloyd Williams.
Jonathan Davies vs. Brian O’Driscoll
O’Driscoll’s break saw him get on the outside of Davies to set up Zebo for the first try of the game. The former Irish captain showed his experience and undoubted talent in a man of the match display to silence the critics in what may be his last Six Nations. Opposite number Davies misplaced a couple of first half passes when Wales were on the attack but became more dangerous as Wales battered the Irish try line.