If and when it happens, Wales will have a new national holiday.
There have been close calls as All Black skipper Richie McCaw discovered in his first leadership foray at the Millennium a decade ago.
Somehow the All Blacks found ways to maintain their winning sequence as Wales chipped into the coaching know-how of Graham Henry, Steve Hansen and now Warren Gatland. The Welsh wait goes on.
They've had dips in expectation but there is a rising belief as they gather new players and head into their next World Cup cycle.
Halfback Rhys Webb is a new talent who echoes that confidence when he looks at the All Blacks.
"They've been getting a bit flustered when people have been going at them," he said.
"I think if we implement our game-plan, not take a backward step and really get into them I think we can put on a good show."
Let's translate that. Is Webb delivering a bit of rhetoric to keep face with the principality's rugby supporters or does he really believe Wales have the cattle, class and conviction to beat the All Blacks?
A piece of fortune, a refereeing decision (on the cards with Wayne Barnes), a slice of great skill or a complete day at the office will get Wales to the victory podium at some stage. They look to the east in envy where England clipped that ticket at Twickenham in the All Blacks' final game of 2012.
Wales were the tourists' entree before that game and were well beaten yet, four months later, back in the comforting surroundings of the Millennium Stadium, they crushed England 30-3 to take the Six Nations crown.
They are in that sporting citadel tomorrow to face an All Black side which has paced their men for this final assault. Both sides rested troops last week and claimed patchy wins. Wales have size, they have pace, they are very fit but ...
How are their minds? Are they uncluttered, have they got the top two inches sorted or will doubt infest their thinking as they arrive to the boisterous pleas of their supporters. Will they breathe fire if they sight history or fall in a hole like their Irish brothers last season?