There was a moment in the first game of Andy Farrell's tenure against Scotland 13 months ago that suggested the transition in styles would be easier said than done.
Andrew Conway received the ball inside his own 22. For the previous six years, the Joe Schmidt method would have demanded Conway put boot to ball.
However buoyed by a newly-granted freedom to express himself, Conway instead shifted the ball wide to Jordan Larmour in search of a counter-attack.
The crowd perked up. They had not seen this in a while. They soon fell quiet though as Larmour put a foot in touch allowing Scotland a line-out in Irish territory.
Ireland's move towards Farrell's vision has been fraught with frustration and, particularly in this season's Six Nations, question marks. Those inside the camp insisted they were on the right track and not far from putting everything together.
It was a position that, as Johnny Sexton noted post-match, most on the outside were sceptical of. If the evidence from the training pitch and team meetings pointed to an upward curve, the performances on the pitch were far less conclusive.
Their win over England on Saturday is vindication for Farrell, Sexton et al. Not in the absolute sense, that would come with consistently producing that level of performance, but vindication in the sense that Ireland showed they absolutely have the capability to cut loose and overwhelm top-level opposition while implementing their desired style of play.
"Apart from the first five or 10 minutes, it was the performance that we wanted to produce against one of the real top sides," Sexton reflected.
"I was sick of coming in and talking to you guys [the media] every week, defending ourselves and saying 'we're not that far away, we just need to do this slightly better'.
"We set a standard in some areas that we need to keep for next November or a summer tour and then into next year's Six Nations.
"We've got to keep getting better and now we have to strive for consistency."
Earls try lights the touch paper
There was nothing off the cuff about Keith Earls' try. The satisfaction of that score would have been as keenly felt in the coaches' box as it was on the pitch.
The play was executed perfectly, from Rob Herring's long throw to Jack Conan's touch down while under duress from Tom Curry, and Earls' perfectly hit line that allowed him to leave a squared-up Jonny May for dust.
"It's something we'd worked on all week," said Farrell.
"You're always trying to find a way of how to win the line-out cleanly and secondly how to manipulate a defence on the back of that."
It came off perfectly and was the spark that ignited Ireland's command of the game after a fairly even opening exchange.
It was the first glaring indication that this was not going to be a repeat of the previous four encounters. In that moment, minds were cast back to Ireland's strike play against France that saw James Lowe touch down in the corner, only for a video replay to show his foot being dragged into touch milliseconds before grounding.
It is impossible to know what impact that try, had it been awarded, would have had on the overall picture of that game. But in such moments games are changed.
Perhaps in an alternate universe Curry did enough to disrupt Earls' score against England and Ireland did not take that chance to seize the momentum.
When Ireland's players and coaches talk about being close throughout the Championship, they were referring to those moments that nearly came off but didn't, which they believe would have shifted the balance in their favour.
"When you look at that French game for example, if you score a try like Lowey - went in in the corner but his bootlaces were a millimetre in touch - the difference that can make to a game," said Sexton.
"It's fine margins and a lot of people speak about them."
'We're on the right track'
Any win against England would have changed the narrative surrounding the side, but a victory delivered in the emphatic manner of Saturday's game will have seen Farrell's opinion ratings skyrocket.
Fans like this Ireland: an exciting, fast-moving, suffocating Ireland playing with adventure and purpose. Crucially, now fans - not just the players themselves - know this side under this management are well capable of delivering such a performance.
"The lads have always believed in how they're progressing and they've always thought there was a performance like that in them," Farrell said.
"The lads really believed that they are making good strides and attack is always the one that gets puts under the most pressure in a Test match, and it is always the last piece of the jigsaw.
"It solidifies for us that we're on the right track."
A triumphant win, with the caveat that it still comes in a Six Nations that is likely to yield a third place finish.
To date, it is undoubtedly the pinnacle of Andy Farrell's reign. But in a year's time, Farrell, and Ireland, will be hoping their win over England in March 2021 was a milestone rather than a finish line.
As 55,000 people inside the Aviva Stadium would in normal circumstances have attested, it is a win to galvanise Irish rugby.