Typically, when the All Blacks take centre stage before kick-off to perform the haka, a packed stadium will feast their eyes on the cultural performance.
But the Irish-dominated crowd stole the show before their side faced defeat at Saturday night's Rugby World Cup quarter-final against the All Blacks.
They drowned out the haka with folk ballad Fields of Athenry, with some saying it was disrespectful.
But haka expert Wetini Mitai-Ngatai disagreed, describing the Irish singing as "fantastic".
"I thought it was lovely, it was beautiful," he told TVNZ1's Breakfast today. "I thought it was nice to bring a bit of Ireland."
Mr Mitai-Ngatai says it's good to come together to witness different cultures and that the Irish singing most likely inspired the All Blacks.
"I enjoyed the clash," he said.
"Everybody was inspired, everybody was nervous."
The All Blacks knocked the Irish out of the tournament as they romped to a comprehensive 46-14 win in Tokyo.
The back-to-back world champions will play England this weekend in the Rugby World Cup's semi-final.