When a game is won at such a canter it seems strange to talk of miracles.
But as Alun Wyn Jones raised the Six Nations trophy into the teeming Cardiff skies on Saturday, gold and red streamers cascading down from the stands, flame-throwers lobbing light into the gloom overhead, the great coup of Warren Gatland's Wales was there for all to see once again.
The 25-7 thumping of Ireland was one thing. A cool-handed defusal of a contest that was supposed to be a nail-biter; a team that not long ago beat the world champions reduced to error-strewn disarray.
Its consequence - a third Grand Slam in 11 years, a record-breaking fourth in the Six Nations - is quite another.
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No other coach in the tournament's history since four became five has won three Slams, and yet Gatland has done this from soil that is not only often barren but frequently scattered to the winds.
Welsh domestic rugby is skint, a permanent crisis that defies easy solution, its best players courted across its borders. Not one Welsh region has made the knock-out stages of a Champions Cup that features Leinster, Munster and Ulster. New dawns are as bleak as the nights that preceded them.
From this Gatland has now built three unstoppable teams. When he became head coach Wales were ranked 10th in the world and had just been sent packing from the World Cup by Fiji. Since then he has steered them to victory in 43 Six Nations matches, 13 more than any other coach has ever managed.
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Sporting confidence in Wales is fragile. When the national team won the Five Nations title in 1988 and 1994, and the Six Nations crown in 2005, the coaches who had taken them there had departed before a year had passed. It was boom or bust or flatlining at best.
Gatland has created a self-sustaining confidence where before doubt always lurked.
In this championship they were 16-0 down to France, 10-3 down to England and defending on their own line and then under the cosh for almost the entire second half in Scotland. Never was there panic. Never against Ireland did they look like anything but winners. The victory songs were rolling down the steep-sided stands with 30 minutes still to go.
Three times Gatland's sides have had shots at a Grand Slam. Three times they have converted them. England have gone into their final game of the championship unbeaten eight times since 1999, yet only twice have they gone on to win Slams.
If some of that contrast is down to how home and away fixtures have fallen it also speaks of a ruthlessness and remarkable ability to cope with pressure.
This is not an extravagantly gifted Welsh team. Not once in this championship have they scored more than 26 points in a game. England scored 32 or more on four occasions.
Only Italy created as few tries. England scored 14 more. It all matters less than the paltry seven that Wales conceded, almost half as many as Eddie Jones's team.
Gatland has been loyal to his key lieutenant, defence coach Shaun Edwards. You can see why. Each of the three Slams has been constructed around an immovable Edwards defence.
During this 14-match winning streak they have shipped just 19 tries and an average of 13 points per game. It is why Scotland head coach Gregor Townsend called it the best defence in the world and it is why, more than any other single factor, why Cardiff was cavorting again on Saturday night.
It took Ireland until the 82nd minute to breach it, when they had scored at least 20 points in their previous eight Six Nations games. An England side that had conjured up four tries in Dublin and three in the first half-hour alone against France were kept to just one here in their defeat three weeks ago.
Those other Grand Slams were garlanded by dashing superstars. Shane Williams and Gavin Henson in 2008, Williams and Sam Warburton in 2012. There are fine players in this vintage, not least the veterans of the last one, George North and Jonathan Davies, but this is a team defined not only by its coach but its captain.
Alun Wyn Jones is the only survivor of Gatland's first Slam and it is not by fluke. He is the great survivor of his generation, 134 Test caps in and counting, and he is the epitome of a team that is more about collective strength than isolated acts of individual brilliance.
North was forced off early on Saturday with injury. Jones spent three minutes on the turf shortly afterwards after twisting his knee in a ruck, but he was never going to leave.
Tackle after tackle. Always there for a carry. First man back on his feet.
None of it is flashy. All of it is critical. It is Gatland in a red jersey, all relentless work and a deep belief in the strategy and the players' ability and fitness to implement it.
Wales only carried the ball for 47 metres in the first 40 minutes. Despite that they went to the break 16-0 up. You wring out everything you can from what you have and you put points on the board from every chance you work.
There are more beautiful ways of playing rugby but there is nothing as sweet as a Grand Slam and that is the end of any argument. Gatland takes the sum of his teams and tweaks the equation so they add up to so much more.
There are days ahead to ask whether it can be sustained and harvested at a World Cup that begins in less than 200 days. There will be those who rightly point out how abject this Ireland performance was, an ugly matching bookend to their opening loss at home to England but in many ways much worse.
Saturday night was all about what have become familiar totems under this regime. A stadium awash in celebration, a team on a dazed lap of honour, the sweet cliches of song blasting out: Tom Jones, Catatonia, Stereophonics.
On Grand Slam days there is no worrying about the future. It is only about the present. Everything else can wait.