When the All Blacks take the field at Stade de France on Sunday morning (NZ time), they won't just face a rampant Ireland team ranked No.1 in the world - they must also find an answer to their fans.
The Irish support has made a major impact during the Rugby World Cup, far surpassing even the most ambitious expectations.
"It's actually quite emotional to see how the numbers have grown for all of the games," Irish rugby commentator Michael Corcoran told AM.
"They've played two previous games at this venue, State de France. For the South Africa game two weeks ago... stadium capacity is 80,000 and for the South Africa game, there were about 45,000 Irish people there.
"Last week, when [Ireland winger] James Lowe, ahead of the game against Scotland, said he heard there would be about 60,000 Irish, and people scoffed and said, 'This fella can't keep count, where does he get the 60,000 from'.
"When the team came out on the pitch for the game, it was somewhere in the region of 70,000 people supporting Ireland.
"There's a huge telepathy between the team and the crowds - it's a kind of journey into the unknown."
One aspect of the crowd support that has captured the public imagination is the use of the Cranberries song 'Zombie' as a victory anthem. Corcoran explains the roots of that phenomenon.
"It's a Munster rugby song, because the Cranberries were from Limerick," he said. "[Lead singer] Dolores O'Riordan, God rest her soul, was from Limerick as well.
"The crowd started singing it at Munster matches - it's actually an anti-war song and it's a catchy number. Munster fans started singing it and I think the first time they did it was when Munster A played South Africa A in a game last November.
"It's just taken off and been adopted by Ireland."
Even All Blacks lock Brodie Retallick is a fan.
"I think that's one of the awesome parts about a World Cup, the enthusiasm the crowd bring," he said this week. "I've seen them singing the Cranberries - it's a great song, but hopefully they're not singing it on Saturday."
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