Now, with the mystery solved of who the Kiwi is, the pair have reconnected and plan to reunite in London next week.
"We will exchange the shirt then, he's also offered to give me another All Blacks shirt".
The original shirt he was given had been taken off him at some stage during the Rugby World Cup celebrations.
He said an "instant friendship" was made with the New Zealand fan, travelling with a female friend to the tournament.
"As soon as we knew Wales was no longer in the World Cup, we changed our alliance to the All Blacks. This was mainly due to the fact of what nice people we had met that day ... This pair really showed New Zealanders in a fantastic light."
While bonding over the game the Kiwi fan gave the Welshman an All Black shirt to wear - a gift Mr Llewelyn-Jones would like to repay, with a bright red Welsh shirt, if only he could remember his name.
In the excitement of the day, Mr Llewelyn-Jones was separated from his new-found Kiwi mate before he could get any contact details.
"I would just like to trace him and say thank you. What a credit to your country this man is, he left us with a lovely impression of New Zealand.
"I would really like to get hold of this Kiwi to give a gift of a Welsh shirt, so he can support us from the other side of the world when we play."
Mr Llewelyn-Jones would also like to wear his All Blacks shirt again, but in another unfortunate turn of events somebody has since taken it from him.
All he knew about the Kiwi is that he was in Wales for the Rugby World Cup, he had a motor home he was travelling around in and may come from the North Island.
He thought the woman travelling with the Kiwi fan might have been called Dena Rolls and might have been living in London.
It turns out the woman's name was Dayna Rolls.
The Welshman was supporting his home team at the quarter-finals against South Africa on Saturday when he met the Kiwi rugby fan.
"We asked them who they would be supporting in the Welsh game. 'Wales of course' was the reply. So with that an instant friendship was hit off."
Mr Llewelyn-Jones said the friendship was further strengthened after his home team failed to pull through the quarter-final round against South Africa and most of the Welsh present changed allegiance to the All Blacks.
The Kiwi fan then pulled out an All Blacks shirt from his bag for the Welshman to wear.
"I was lucky enough to get a ticket to watch the All Blacks game, a dream to watch the haka live and it was brilliant wearing my All Blacks shirt as if I was part of it, shouting on the winning team.
"I can remember showing this shirt off to people and pointing out the All Blacks logo on the shirt, proud to be on the winning side."