Joe Schmidt is Ireland's creative Kiwi genius; Andy Farrell their not-so-secret weapon.
What a tag team combination this is proving to be.
Twice in the space of 17 months Farrell's defensive systems have prevented the All Blacks, the world's most lethal side, from scoring a try.
To put that feat in perspective it has only been achieved six times this century, in 243 tests.
Prior to this northern tour, the All Blacks had claimed four or more tries in 12 consecutive outings.
Not against Farrell, the dual code international, though.
The second Lions test in Wellington, where admittedly the All Blacks battled one man down for 56 minutes, and, now, in Dublin the score sheet is clean.
"He is delighted, no doubt," New Zealand's Schmidt enthused of his trusted English assistant. "It is so seldom the All Blacks don't score a try."
It's no coincidence Farrell has now been involved in four defeats of the All Blacks – Ireland's maiden victory in Chicago two years ago and England's triumph in 2012, where Steve Hansen's men struggled to recover from a vomiting virus, the others.
Rush defence, not a new phenomenon, is fast becoming commonplace against the All Blacks and evidence suggests Farrell's blend is particularly difficult to combat.
"You get up and you form a line and you get off it so it's not rocket science but it's everyone understanding and committing to their role and trusting others will do theirs," Schmidt said.
"He's doing a great job and I've really enjoyed working with him over the last two-and-a-half years. I'm lucky I've got a team behind the team who do a super job."
On this high-stakes occasion, played in an electric atmosphere, the All Blacks argue they did, in fact, sever Ireland's defence several times in the second half and their attacking execution failed to convert four clear try-scoring chances.
The All Blacks also put themselves under major pressure through ill-discipline, giving away nine first half penalties, and the set piece did not function as is normally expected.
But repeat, uncharacteristic errors from experienced heads, captain Kieran Read and Brodie Retallick among them, summed up just how stifled and frustrated they were at times.
"They don't give you a lot of room and they're well drilled so everyone knows what to do," All Blacks coach Steve Hansen said. "Farrell is good at organising his team to fill up the space on the park and he does that really well."
Even when the All Blacks did get in behind the Irish, another green jersey suddenly appeared as Ben Smith found when Beauden Barrett's grubber was snatched from his grasp with the line open.
"They pride themselves on their defence and we were working on breaking that down," Smith said. "Against a good Irish team you only get a few opportunities and we didn't nail those. You've got give them a lot of credit in the way they defended and their urgency to get back and shut those down.
"The way they bring the line speed to challenge, especially up on the inside, they manage to pressure the skill sets of opposition teams. We have good plans around that and we still managed to get opportunities but that's a big part of their game is to challenge teams in the way they defend.
"Even in the last couple of minutes we were making progress but you've got to give credit to the way the Irish defended. They put us under a lot of pressure and forced us into a few errors at times."
It's not all doom and gloom for the All Blacks.
Under Schmidt, Ireland are crafting a world-class team with heart, belief and depth. In the past year they have hammered the Springboks by 35 points, won a Grand Slam; a first test series in Australia – all before this victory topped it all.
This is, indeed, a golden age.
As for the All Blacks, time for introspection has arrived.
While Ardie Savea featured prominently and they weren't helped by losing Liam Squire early, their loose forward trio was outplayed, with inspirational Irish blindside Peter O'Mahony setting standards.
The final point is the All Blacks have been exposed with switches of play back to the short side this year - Argentina just one team to find success there.
The shrewd Schmidt suggested his lineout switch move for Jacob Stockdale's only strike of the test was plucked from others, citing the Mitre 10 Cup and the Highlanders.
Take that with a grain of salt. It was no surprise this specifically targeted the short side; an area the All Blacks have previously been exposed this season.
"It was well done and when they score a try like that you've just got to acknowledge it was well played," Smith said. "As a team they have got a lot of tricks up their sleeve but we've got to be a bit more on to it with how we defend those tricks and that's an example tonight.
"As a team we'll learn a lot from that and we'll get better."
The missing rugby jersey was found after a two-year search.