It was the sport's day of days, to call it Super Saturday doesn't even begin to tell the story.

International rugby has been with us for more than 140 years, but it had never seen anything like this.

Three matches, 215,000 fans, a UK television audience close to 10 million. Four hours of rugby, 221 points, 27 tries. But even those startling numbers say only a little about the momentous events of 21 March 2015. Wherever rugby is played, and for long as it is played, the date will be talked of in hushed tones.

Strange to think now of how the championship, in its old Five Nations format, used to peter out at the end of the season. Yes, it produced the odd gripping finale, but just as often the winners would be sitting out the final weekend, their title already sewn up. Not that anyone really thought too much about titles. Back in the day, it was really no more than a collection of friendlies.

Not any more though. What we witnessed on Saturday was competition of visceral intensity in the seething cauldrons of the Stadio Olimpico, Murrayfield and Twickenham. Whether you were present in one of those three great cathedrals of the sport or just hyperventilating in your armchair, the climax of the 2015 Six Nations was raw, passionate and utterly compelling. Teh World Cup later this year will be doing well if it produces anything remotely its equal.

When a rugby score goes past 40 points you can usually assume that some calamitous defending has been involved. And, yes, it would be fair to say we saw some of that from Scotland, Italy and France - and even from England at times. But who will remember the day for a missed tackle here and there or the fact one side or the other couldn't quite get their defensive line speed right. The memories will cherish will be of the pace, ambition and bravado the three contenders showed in attack as they set off to build what they hoped would be a title-winning total.

Wales first. George North was just 18 when he announced himself with a brace of tries on his debut against South Africa in 2010. Over the course of 51 Test matches - three of them for the Lions - he had scored a double on another three occasions, but he had never managed a hat-trick. Thrillingly, however, he put that right in the space of 10 astonishing minutes in Rome. With another by Liam Williams, Wales turned a one-point lead at half-time into a 29-opint lead on the hour mark.

The floodgates were open, the gauntlet thrown down. Wales finished with a 61-20 victory, and the meagre +12 points advantage they had brought into the game was now a daunting figure for the other sides to chase. Wales, rank outsiders that morning, looked to be favourites by the middle of the afternoon.

Bu then to Edinburgh, where all the professional chinstrokers had it that Ireland would probably win, but only by a narrow margin and would fall short of the 21-point difference they needed to reel Wales in. But at the end of a disappointing tournament, the Scots were saving their worst for last and Ireland delivered their best. With 61 minutes on the clock, Jonny Sexton nailed the penalty that put Ireland in the championship driving seat.

It was breathless stuff. When Jamie Heaslip's last-gasp try stopped Stuart Hogg claiming a consolation try for Scotland, we could hardly know its significance. At the finish, Ireland's 40-10 victory meant that England would have to beat France by 26 points at Twickenham to take the title. France may have been wretched at times in this year's tournament, but surely they would not be that bad again?

And they weren't. France finally found their gears and were off and running - running as only they can. With 17 minutes played they were 15-7 ahead, with two tries to England's one. England could still come back to win the game, but there was no way they were going to take the title.

Yet they fought desperately to do just that, and the tries started to flow. England finished with seven, all converted by the superb George Ford, and they were breathing down Ireland's neck in the second half. They were still pressing when Rory Kockott, the French scrum-half, slammed the ball into touch to bring the game to a close. It finished 55-35 to England. Six points short of what they needed.

It defied belief. England had never scored more against France; amazingly France had only once scored more against England. Other records had fallen by the wayside as well. It was Wales's highest ever score in the championship. Ireland equalled their record margin of victory against Scotland.

It is the oldest cliché in the book and the weariest line in an after-dinner speech, but rugby really was the winner. Even Paul O'Connell, Ireland's dome-headed colossus, could scarcely take it in. It was a bizarre day, an incredible day," O'Connell smiled. "Maybe someone was smiling down on us."

Maybe so, but it was a pleasure many others were happy to share on this unique rugby day.