Three moments in first four minutes proved Ireland were always going to beat England
At 4:06, Ireland and England were tied at 0-0 but the game was already swinging one way. By 4:58 that swing was comprehensive.
There is always something unsettling about being in the middle of Twickenham during the national anthems. The pomp, ceremony and sheer brio with which God Save The Queen is hollered out is enough to convince you that you are in the beer-fuelled maw of the British Empire.
Brass bands, army, navy, St George's flags everywhere and the majority of the 80,000+ crowd strutting around like they are the sole protectors and owners of the rugby game they spawned nigh on two centuries ago.
To be an Irish player in the jaws on this immense stadium is to know every inch - bar the solace of your dressing room - is enemy territory.
The men in green go for Ireland's Call on away trips - Amhrán na bhFiann reserved for days at Lansdowne Road when the IRFU call the shots - so it was that song that Joe Schmidt's team tore into. Jack McGrath was doing a bad job of holding back the tears while Garry Ringrose and Peter O'Mahony both took in huge gulps of air to calm themselves.
The thousands of Irish fans in attendance, in noisy pockets across the ground, would do their best during the game but this one would rest on the shoulders of the players, and their coaches calling some of the shots from the stands.
Johnny Sexton had the task of kicking the Grand Slam decider off and he was made wait for over a minute, on halfway, as referee Angus Gardner awaited the green light from the broadcasters. Eventually, thankfully, he got the nod and we were underway.
Heading into the match, Dan Leavy had been highlighted by some in the English press as a potential weak link. A talented player, yes, but no Sean O'Brien. Twickenham would be his biggest test.
How did he respond? His first carry drove back George Kruis and Dylan Hartley, and he continued on in a similar vein for 82 excellent minutes.
With Cian Healy and Tadhg Furlong latching on to power Leavy forward, Ireland were motoring already.
The very next carry after that did even more damage. Owen Farrell had been shifted up from inside centre to outhalf and immediately saw more traffic come his way, in the shape of the rampaging Iain Henderson.
Much as he did to Eben Etzebeth, the giant Springboks lock, last November, Henderson steamrolled the England No.10.
Sam Simmonds, Ben Te'o and Kyle Sinckler were all then sucked in after Farrell was bounced.
There's a statement for you!
That early momentum was squandered when CJ Stander knocked on with the next play, giving England the ball back. It was Ireland's turn to absorb some charging bodies but they did so comfortably.
The next big moment arrived on 4:01 and it involved England captain Dylan Hartley again.
Scrum-half Richard Wigglesworth signalled for Hartley to make a carry but Leavy and James Ryan were waiting and, mother of God, then they smash him back.
Ryan did most of the damage - and would go on to do more all afternoon - as Hartley made minus two metres on the carry.
That fierce defence saw Farrell phase pressure in an attempt to pin Ireland back in their 22. He was not counting on Kearney's innate ability to be in the right place and the right time. His kick through the Irish lines was gathered by the fullback and Farrell left one on him as he kicked clear.
Penalty Ireland and Sexton hit the line to give Rory Best a throw. Ireland were fortunate with the lineout as it popped back to Best but within 48 seconds and three phases Garry Ringrose was scoring their first try.
That was the reward for a start in which Ireland met fire with some of their own but also had a clear-headed idea of how to win this fight.