Shane Williams' try in the third minute was an indication of what was to come.
Wales played with depth, hit passes hard and were prepared to be expansive, meaning the Irish defence was punished in the early stanzas. It was a regulation finish for the country's all-time top scorer.
The smarting Irish responded, eventually dominating the first half territory and possession - but not managing to score. They were prepared to employ the unusual tactic of opting out of shooting for penalty goals, not once but three times. All three attempts would have been from near the sideline, and the swirling wind needed to be considered, but it was a bold plan.
First-five Ronan O'Gara kicked for the corners instead but they were unable to pierce the Welsh defence, at least in the first half. Flaws in their skills set with knock-ons and other errors prevented them pounding the Welsh line for any sustained period.
A number of pundits felt the match would be won at the breakdown but opensiders Sam Warburton and Sean O'Brien and their respective cavalries largely cancelled each other out as they swarmed to retain possession. Likewise at the scrum, neither side demonstrated any resounding dominance.
The Irish territory advantage in the first half was diminished by lateral movement and a lack of attacking variation, rather than progression up field.
That was in part due to the hesitation at the ruck before distribution from the likes of halfback Conor Murray, a problem that has hampered a number of teams at the tournament. It allowed the Welsh to re-gather and co-ordinate themselves to nullify the Irish raids.
The Welsh also proved too smart to fall into the trap made for the Wallabies where they held up mauls and earned a scrum feed for their trouble. Wales were quicker to hit the ground and recycle. Mike Phillips' crisp service unleashed Jamie Roberts numerous times in midfield; a formidable assignment for any defender.
Brian O'Driscoll and Gordon D'Arcy offered what midfield penetration Ireland managed through the varied run/kick/pass tactical plan from O'Gara - until he opted to sending wipers punts for the corners later in the first half as he willed the Welsh into making mistakes in their own 22. They didn't, despite having to make 85 tackles compared to Ireland's 46 and conceding six penalties to two.
Ireland seized momentum shortly after the break with Keith Earls' intelligent low dive into the corner which - with an O'Gara conversion - levelled the scores. But Wales soon showed, with the southerly behind them (as much as it can be in the swirling Cake Tin), they were determined to get into the Irish 22 and stay put.
With the territory controlled, points came too. Phillips continued a strong display with a dive to echo the scoring lunge of Gareth Edwards' 1973 Barbarians effort in the 50th minute. He planted the ball firmly in the corner to stretch the lead to 15-10.
Jonathan Davies' effort saw the Irish defence wilt under the pressure in the 65th minute and gave Wales vital breathing space.
Wales 22 (S. Williams, M. Phillips, J. Davies tries, R. Priestland 2 con, L. Halfpenny pen) Ireland 10 (K. Earls try, R. O'Gara con, pen). Halftime: Wales 10-3.