It was Tomás Ó Sé who coined the phrase “you hammer the hammer” in reference to beating a team by targeting, and thereby negating, their primary strengths.

Ireland ran hard, Wales held firm. 289 times.

Irish and Welsh men took to the skies on four occasions in the first half and each time the ball returned to earth in a red embrace. Leigh Halfpenny leapt over Conor Murray, Jamie Roberts cleanly beat Rob Kearney in the air.

"They won the first four balls in the air so they did very well," said Joe Schmidt. "You can't take anything away from Leigh Halfpenny and Jamie Roberts in the way that they did that."

Paul O’Connell was pointedly asked if he knew on what grounds Wayne Barnes awarded Wales a scrum penalty in the 80th minute.

“No,” replied the Irish captain.

The statistics pouring out of this test match are astonishing. Wales made 289 tackles, missing 22, for a success rate of 92 per cent. To put that in some context Ireland made 143 tackles, with a success rate of 85 per cent, in last November’s 29-15 defeat of the Springboks.

Luke Charteris made 37 hits with zero missed and, as his defence coach Shaun Edwards highlighted afterwards, did an amount of work elsewhere. Particularly his excellence out of touch.

Charteris's tackle count is one shy of Thierry Dusauotir's "world record" (we're going to qualify that within a major international fixture) of 38 in perhaps the greatest upset in the sport's history – France beating the All Blacks also at the Millennium stadium in the 2007 World Cup quarter-final.

That's where this defensive showing now ranks. The Wales backrow combined for a neat total of 75 tackles. Man-of-the-match Sam Warburton contributed 30 of those. And an amount of work elsewhere.

Wales even survived the sin binning of Warburton (losing 6-3 in that ten minute period) and when Jonathan Davies’ was dismissed at the death they conceded nothing.

Wales devoured at least four Irish throws, Rory Best struggling on two occasions to hit the barn door that is Devin Toner, with Paul O'Connell recognising as much afterwards.

“They got Luke Charteris up the front and nicked a few off us, particularly the five metre drive early on. Good position. They did to us what we did to England two weeks ago.”

Never has the well worn swings and roundabout phrase proved so apt in a Six Nations campaign.

“It’s such a disappointing place to lose the ball,” O’Connell continued. “Even if you don’t get your maul set up at least you have ball five metres out. To lose the ball and then concede a penalty to allow them clear their lines was a big momentum changer.”

That came after seven (50-57th) minutes of sustained Irish pressure. It was Jonathan Sexton going over the top in a ruck that led to both Welsh players and crowd celebrating like they had crossed Ireland's try line.

They may as well have.

Schmidt mentioned the lack of penalties coming off Barnes’ whistle in the second half, and he noted the raft of Irish line breaks, including two big carries by O’Connell but Ireland have not had to chase a match this season.

“I don’t think in the championship you can go anywhere and start chasing points,” Schmidt agreed.

It was uncharted territory. So was the need to adopt a looser, attacking strategy when down 20-9 after Scott Williams raced between Jamie Heaslip and Tommy Bowe.

“A mix up between us,” said Bowe. “Need to see it again. Suppose it was a soft try.”

There were four offloads made by Irish hands. Nothing worth noting, nothing that ripped the Welsh line apart.

“There were a few opportunities for offloads but not many,” added Bowe.

It finished with an unfinished question, about going back to the drawing board, or not as the case will prove, which didn’t exactly warm Schmidt’s cockles.

“I don’t think we need to go back to the drawing board . . . there was still a fair bit of good with the game. I think if you start to throw the baby out with the bath water, you know, it’s pretty hard to start all over again.”

No need for such a dramatic rethink, a championship can still be won.

England have a superior points difference - plus 37 to 33 points with Wales heading to Rome on plus 12 – so plenty to mull over.

Bowe added: “It’s the first opportunity for an Irish team to win back-to-back championships so there is still a huge amount to play for, a massive match in Murrayfield. We’ll be pumped up for it.”