The shock inclusions of NRL stars Jason Taumalolo and Andrew Fifita makes Tonga a genuine threat for the World Cup, according to tournament favourites Australia and New Zealand.
A day after 2016 Dally M winner Taumalolo turned his back on the Kiwis, Fifita joined the crusade by knocking back a Kangaroos jumper to play for the country of his heritage.
In doing so, both players also cost themselves up to $50,000 in match payments for tier-one nations.
The duo were on Thursday named in a strong 24-man squad, including Michael Jennings, Konrad Hurrell, Manu Ma'u and Will Hopoate.
Tuimoala Lolohea and Ata Hingano are the likely halves.
New Zealand took the high road when they described Taumalolo's defection as a boon for international football, leading Kiwis coach David Kidwell to declare Tonga a real contender.
"I think everyone's mindset is that they're going to be thinking they're genuine contenders for the World Cup — we definitely think [they] are major contenders," Kidwell said on Thursday.
Kangaroos' rookie Wade Graham said he also considered Tonga a serious challenge.
Should Tonga finish top of group B, which includes New Zealand, Samoa and Scotland, they could meet Australia in the final in Brisbane.
"They're definitely a great team. [Taumalolo and Fifita] certainly add to any team they play in. Obviously a lot's happened today [Thursday]. It's all hard to digest right now," Graham said.
It was only last year when the Rugby League International Federation relaxed eligibility rules to allow players from tier-one nations to play for developing league countries.
The move has paved the way for Jarryd Hayne to appear for Fiji and James Tedesco to play for Italy.
Rugby League World Cup boss Andrew Hill said it was a perfect endorsement of the game.
"From that point of view, it's a fabulous promotion of where rugby league is at the moment and the growth of international rugby league," Hill said.
RLWC's nation swappers
- Jarryd Hayne: A certainty to be picked for Fiji. Has played 12 Tests for Australia.
- Robbie Farah: Made international debut for Lebanon in 2002. Played eight Tests for Australia but will turn out for The Cedars.
- Felise Kaufusi: Is playing for Australia but has played for Tonga.
- Josh Mansour: Selected for Australia but has played for Lebanon.
- Addin Fonua-Blake: Selected for New Zealand but has represented Tonga.
- Tyson Frizell: Playing for Australia has also represented Wales.
- Josh McGuire: Part of the Kangaroos squad but has played for Samoa.
- Reagan Campbell-Gillard: Playing for Australia but has for Fiji.
- Isaac Liu: Playing for New Zealand but has represented Samoa.
- Jordan Rapana: Will be a Kiwi but has played for the Cook Islands.
- Brad Takairangi: Playing for New Zealand but has featured for Cook Islands.
- Martin Taupau: Playing for New Zealand but has played for Samoa.
- Manu Vatuvei: Will play for Tonga but has previously been a Kiwi.
- Michael Jennings: Part of Tonga's side but has played for Australia.
- Siliva Havili: Is playing for Tonga but has represented New Zealand.
- David Fusitu'a: Part of Tonga's team but has played for New Zealand.
- Solomone Kata: Playing for Tonga but represented New Zealand.
- Tuimoala Lolohea: Playing for Tonga but has played for New Zealand.
- Sika Manu: Part of the Tongan side but has played for New Zealand.
- Manu Ma'u: Playing for Tonga but has represented New Zealand.
- Sam Moa: Representing Tonga but has played for New Zealand.
- Sio Siua Taukeiaho: In Tonga squad but has played for New Zealand.
- Daniel Tupou: Selected for Tonga but has represented Australia.
Graham insisted it was only a matter of time before emerging nations would be challenging the tier-one nations on the world stage.
"Slowly we see the emerging nations starting to dominate with individual players and groups of players. It's definitely added excitement," he said.
"It's created another talking point for the build-up of the World Cup. It's only going to be a good thing for our game."