Wales dominated the encounter yet had to wait until the 57th minute to pierce the Irish defence with the elusive Williams dancing over to wrestle the Triple Crown from their opponents.

It was the Ospreys winger’s 40th Test try, equalling the record set by Gareth Thomas, and lifted his remarkable strike rate to 11 tries in eight games.

Llanelli fly-half Stephen Jones contributed two penalties and a conversion while his eventual replacement James Hook weighed in with a late three points.

Wales controlled long passages of play, refusing to give up possession, but Ireland’s muscular defence held up impressively until Williams’ moment of magic.

Warren Gatland had identified Ronan O’Gara as Ireland’s main dangerman and his assessment was proved correct as the Munster fly-half continued his imperious run of form.

He slotted four penalties in four attempts and his kicking from hand was one of Ireland’s few sources of refuge from the relentless Welsh assault.

But even the majestic O’Gara could not conjure the crucial try as the mediocrity around him ensured the Welsh line was seriously threatened only once.

Wales played a quarter of the match with 14 men following the sin-binning of Mike Phillips and Martyn Williams but Ireland could still not break through.

Expectation over the match had been heightened by O’Sullivan’s prediction it would be the clash of the RBS 6 Nations, but the high-octane thriller failed to materialise.

Much of the focus in the build-up was on the intriguing sub-plot of Gatland’s return to Dublin, the setting for his dismissal as Ireland boss in 2001.

O’Sullivan replaced him and the manner of his exit left Gatland seething with resentment, directed largely at his successor’s perceived role in his downfall.

But the Kiwi left Dublin with the comfort of having avenged his acrimonious departure in the way that will have hurt his former paymasters the most.

A petty series of mind games – most of it stemming from the Welsh camp - preceded the build-up but Ireland seemed to have taken little notice as they made a strong start.

With just seconds on the clock, O’Gara rejected the chance to kick at goal and drilled the ball into touch.

They won the line-out and spent the next three minutes inching up field, eventually forcing a frustrated Wales to concede under the posts and this time O’Gara took the three points.

The Welsh reacted swiftly when Ireland sought to press home their early superiority and became over-stretched, but Rob Kearney was on hand to clean up Mark Taylor’s chip.

The pressure continued however with John Hayes – who has been enjoying an impressive Six Nations – penalised for not binding at the scrum.

Jones accepted the routine shot at goal but pushed it wide, Wales’ first missed penalty of the championship.

Hayes’ Munster captain O’Gara has also been in imperious form and one beautifully-executed chip pushed the red shirts onto the back foot.

The Lions fly-half punished another Welsh infringement to extend the lead and then produced a magnificent touchfinder that bounced off the corner flag.

Wales were buckling and appeared to have cracked in the 23rd minute when Shane Horgan skipped his way past two defenders and dashed for the line.

But last-ditch intervention from scrum-half Mike Phillips forced him to drop the ball just before the line and television match official Dudley Phillips spotted the mistake.

Horgan lacked the pace to finish the chance he created and soon after Stephen Jones found his mark with a penalty to complete a potentially crucial 10-point swing for Ireland.

The balance of power continued to shift as superb handling and offloads from Wales – with Tom Shanklin prominent – began to force some openings.

Full-back Lee Byrne was shoved into touch five metres short of the line and Wales then created a large overlap but Kearney scrambled to avert the danger.

Ireland repelled waves of attacks yet there was no sign of their defence splitting as Wales kept the ball in hand and probed for weaknesses.

It was going to take something special to pierce the green wall and captain Ryan Jones almost provided it was a bulldozing run from the base of the scrum.

Stephen Jones took the ball on and the Irish infringed, offering Wales an easy three points that were snatched away when Mike Phillips was seen dropping a knee into the back of Marcus Horan.

The linesman alerted referee Wayne Barnes and the English official produced a yellow card, leaving Wales with nothing to show for their dominance.

Stephen Jones was on target six minutes into the second half, however, as the Welsh continued to pound away with a huge kick from Gavin Henson cranking up the pressure.

Finally Ireland gave way, Shane Williams taking Stephen Jones’ pass and slipping out of the clutches of Andrew Trimble and beating a despairing lunge from Kearney.

The try was thoroughly deserved given Wales’ stranglehold on the game but the Irish were offered a glimmer of hope when Jamie Heaslip surged into space.

In the midst of the scramble to halt the Leinster back row, Martyn Williams executed a cynical trip on Eoin Reddan and was dispatched to the sin-bin.

O’Gara slotted the penalty to slash the deficit to 13-9 and then added his fourth of the afternoon to set up a grand stand finish.

O’Driscoll was limping badly, patrolling the right flank at a snail’s pace as he attempted to run off the injury to his right leg.

He conceded defeat in the 71st minute and was replaced by Luke Fitzgerald and Ireland’s hopes finally evaporated when Hook landed a long-range penalty.

Wales face France in Cardiff next Saturday where they will be seeking to complete the Grand Slam they last won in 2005.