Saturday in the Aviva Stadium was the stuff of legend. At 5pm it was reasonable to assume that nobody in the 50,000 crowd thought Ireland could win and indeed had the Irish bookmaker famous for his marketing stunts offered a free €100 bet to everybody in the audience, he might not have lost his shirt.
This performance matched anything in the cinema, music or politics. The disgraced politician Charles J Haughey once described an extraordinary chain of events as Grotesque, Unbelievable, Bizarre and Unprecedented. Supporters of the Irish rugby team more than matched his real-life experience.
It was grotesque to watch South Africa to revert to a game plan of 20 years ago where they abandoned any pretence to the new open game that had defeated New Zealand.
As the substitutions came thick and fast, the new arrivals, Adriaan Strauss, Bakkies Botha and Schalk Burger, were throwbacks to the power game of the Afrikaaner past.
It was also bizarre to watch the visitors make rudimentary errors. Scrum-half Francois Hougaard fumbled and fiddled and destroyed any hopes of continuity. It reached a nadir when full-back Willie le Roux dropped the ball without a defender in sight.
They were not alone. The mighty Springboks were a disorganised rabble without any semblance of leadership from captain Jean de Villiers or veteran Victor Matfield.
To the watching faithful, the unbelievable was happening in front of their eyes.
Ireland led throughout the game despite South Africa being the dominant team.
The Boks had over 60pc of the territory, forcing Ireland to make twice as many tackles and the Irish scrum threatened to be an embarrassment. Yet Ireland were never headed and a masterly game plan won out.
This was unprecedented and may get better. Joe Schmidt in 12 months has a moral victory over the All Blacks, a Championship and now beaten the second-ranked country.
Were he to fashion a victory against Australia in two weeks, he would have achieved a series of performances unmatched in the long history of Irish rugby. To prove superior to the might of the southern hemisphere is quite simply beyond compare.
To put the achievement in perspective, Warren Gatland, since taking charge of Wales in 2007, has won only one of 26 matches against the three southern hemisphere powerhouses.
Music is about interpretation. Every New Year the Vienna Philharmonic presents a programme from the vast repertoire of the Strauss family. The extraordinary achievement of Saturday was that unlike conductor Zubin Mehta, Schmidt absolutely choreographed a perfect performance from a distance and without a baton.
On Friday in Dublin at a charity event, Andrew Trimble suggested that the Irish coach demanded complete adherence to his game plan and techniques. Clearly Schmidt's authoritarian style has, unlike some of his predecessors, got a magical ingredient that has won over the players.
One imagines that after the last 12 months there will not be a dissenting voice in the dressing room.
There were echoes also of a movie script on Saturday. I wonder did IRFU president Louis Magee reprise Humphrey Bogart in 'Casablanca' and gleefully exclaim, "Of all the unions, in all the towns, in all the world, he walks in to mine." Some of the contract negotiations with Irish players have lacked subtlety. Hopefully, they have it right with this man who in a short time has made such an impression.
Interestingly, the try in dying minutes by JP Pietersen may have denied Ireland third place in the world rankings. A win by 15 points would have catapulted Ireland over England and Australia. Fourth place ahead of England now seems likely.
The real test of a coach is how he performs with a team not in the front rank. I hugely underestimated Schmidt because I wondered how much was due to the quality of the players at Leinster and the groundwork done by Michael Cheika.
On the back of England winning the Rugby World Cup in 2003, the coach Clive Woodward went on to fame, fortune and a knighthood much to the chagrin of the players, who felt their contribution was diminished.
The victory, if not conclusive of Ireland's place in the pantheon of great teams, conclusively proves Schmidt's right to be determined as one of, if not the best, coach of the Ireland rugby team.
Jonathan Sexton was correctly hailed as man of the match but three player selections and their performances were worthy of an award.
Mike Ross was herculean in his endeavours to survive in the scrum and last 80 minutes which was a half an hour longer than most expected. The centre partnership of Jared Payne and Robbie Henshaw was magnificent and the Connacht player won the battle to partner Gordon D'Arcy against Australia.
In the old amateur era after a particularly fine performance by Ireland, the chairman of selectors went in to the dressing post-match and announced an unchanged line-up for the next game.
He was informed in due course that his fellow selectors might have something to say about that. I suspect that Schmidt will not name the same team in two weeks.
It is a different opponent, with a different style and one that unlike the hapless Boks is going to come prepared to play.
Twenty-five years ago, "the Wall" came down. In two weeks, the wall of invincibility of the nations south of the equator could come down and like Humpty Dumpty never be put back together again.