Wairarapa United have been kicked out of the Chatham Cup and Napier City Rovers reinstated after New Zealand Football judged United guilty of fielding an ineligible player.
NZF ruled that Brian Kaltak, who came off the bench in United's 2-1 defeat of Napier, should not have taken the park.
Teams can field a maximum of three guest players - generally defined as non-New Zealand citizens or residents who have not resided in NZ continuously for the past 12 months.
Wairarapa applied to have Vanuatu's Kaltak reclassified as a guest player in time for the Napier game and NZF granted the request based on the evidence provided by the club.
But it has since surfaced that Kaltak was outside the country when the application was made, only arriving back in NZ on June 14, two days before the match and two days after Wairarapa's request was submitted.
Kaltak spent the summer playing for Solomon Warriors in the OFC Champions League without being properly registered.
No international transfer certificate was obtained for the teenager to play in Vanuatu, something that would have alerted NZ parties to his ineligibility to be reclassified as a guest player.
The decision is subject to appeal and any such actions will be considered under urgency.
Earlier this season, Christchurch clubs University and FC Twenty11 were both disqualified from the competition for fielding unregistered, and therefore ineligible, players in their first round meeting.
"It's another unfortunate reminder of the need for clubs to be vigilant when preparing evidence for transfers, player registration and players status changes," said NZF's competitions manager Chris Kemp.
"The onus is on clubs to be on top of things when doing their research and ensuring players meet the requirements of the competition in which they are playing."
Rovers will now take Wairarapa's place in the fourth round, playing Palmerston North Marist away on Saturday.
Wairarapa coach Phil Keinzley told The Dominion Post on Friday that he was confident the club had not broken any rules.
Who was the best player at the World Cup?