Tonga believe they were denied a legitimate penalty try in yesterday's Rugby World Cup match against Argentina that could have changed the course of the game.
The 'Ikale Tahi are all but out of playoff contention after a 28-12 defeat by the Pumas in Higashiosaka left then winless and without a point after two games.
Argentine hooker Julian Montoya bagged a hat-trick inside 25 minutes as the South Americans raced out to a 28-0 lead.
The 'Ikale Tahi were given a lifeline just before the half-hour mark when fullback Telusa Veainu weaved past two defenders to score their first try of the tournament.
David Halaifonua was denied another try in the final play of the half, with referee Jaco Peyper ignoring Tongan appeals to award a penalty try for a no-arms tackle.
After viewing the replay and consulting with the TMO, the South African whistleblower ruled Pumas lock Tomas Lavanini did wrap an arm around the the ball-carrier, however Tonga coach Toutai Kefu saw it differently.
"I thought it was a try. I thought it was a shoulder charge," he said.
"If we would have got that we would have come out in the second half with a lot more belief and confidence (but it) wasn't to be."
"He went to hit with the left shoulder (but) wrapped his right arm so I think that's why it probably got called off. That's what I'm thinking - I don't know - but we play the referee's decision."
Veteran flanker Sione Kalamafoni said Tonga failed to execute basic skills during the first half but agrees they were denied a deserved try on half-time.
"The decision should be in our way. It is a clear shoulder (charge) I think,"said the Leicester Tigers backrower.
"But they make the decision and we have to play along with it so we can't change those decisions, and hopefully we get those decisions in the future in our way, in our favour."
Toutai Kefu said it felt like Tonga did not get the rub of the green from the officials.
"There was a couple of 50/50s today I thought we didn't get, maybe that one being one," he said in reference to the disputed penalty try call.
"That was critical for us too. There was a few other decisions as well - there was was that head-high, the high tackle on you (turning to captain Siale Piutau).
"But you actually watch it on the replay and he hits on the chest first and then creeps up, so I thought that was a bit harsh, but I'm used to it (after) four years (coaching a) tier two so you just move on."
Telusa Veainu scored his second of the afternoon with 15 minutes remaining but, despite keeping the Pumas scoreless in the second half, it proved too little too late for Tonga.
Toutai Kefu said poor skills and too many basic errors in the first 25 minutes effectively cost them the game but he was encouraged by the way his players responded after half-time.
"We didn't give up. We could have come out in the second half and thrown the white flag up but the boys dug in," said the former Wallabies number eight.
"We were on our tryline there for a good period of that second half and the boys did really well to defend that tryline for about 10 to 15 minutes, so it just shows the character of the boys and they're willing just not to give up and keep fighting."
Kefu said Telusa Veainu made a big impact in his first test for almost three years, providing the 'Ikale Tahi with some much needed potency with the ball in hand.
"He offers us x-factor out wide so it's great to have him back," Kefu said.
"I remember his last game he played for us (in November 2016) - he actually won the game for us against I think it was USA, so having a player of his calibre and class is fantastic for us."
Captain Siale Piutau said there are still some positives they can take forward into their penultimate pool game against France next weekend.
"Compared to last (when we) didn't throw any punches, we felt like we didn't have any ways into the game, whereas today we converted some tries," he said.
"I think negatives: obviously we can't let tier one teams get a headstart like that so we've got to be more clinical. We gifted them two tries and that was the make or break of the game."
Tonga must now beat France and the United States in their remaining pool matches and hope other results go their way to have any chance of reaching the quarter finals.
Sione Kalamafoni said while it might be unlikely they will keep trying.
"If it's still possible we can still have that mindset and that goal within us. Obviously if we have that still on then we will fight for it."