A yellow card was upgraded to a red during a Wales game for the first time due to a "high danger" act committed by Japan U20s' captain.
It was announced prior to the World Rugby U20 Championship kicking off that the new system would be in place for all games, with reports saying it could be implemented at this year's Rugby World Cup too.
The TMO bunker system allows a yellow card to be upgraded to red. Players who commit a definitive red card offence can be sent off immediately, but for incidents which require closer attention, referees can send them to the sin bin for an initial 10 minutes while the incident is reviewed off the field. It allows the game to be sped up, and has already been trialled in Super Rugby this season.
In Wales U20s' match against Japan on Thursday, inside centre Yoshiki Omachi hit a stationary ruck which was loaded with five Welsh players "like a missile", and was initially shown a yellow card.
The commentator explained: "I'm not sure, exactly, what he is trying to achieve there."
The co-commentator responded: "Yeah. iI's a dead ruck, they've got five numbers in there, he needs to just leave it alone."
However, after some close consideration in the TMO bunker by South African Quinton Immelman, the illegal clearout was upgraded to red just a few minutes later.
You can watch the incident below:
Referee Morné Ferreira said: "So the yellow card's been upgraded to a red card, with high danger and no mitigation, so it's a red card."
The commentator explained: "That's bad news for Japan. They have lost their captain permanently. Quinton Immelman has had a look at it in the bunker. He [Omachi] cannot believe it, but he has to accept it because Yoshiki Omachi has been red carded for that challenge on Evan Hill at the breakdown. Japan will play the last 28 minutes with 14 men."
The system was actually used to upgrade a yellow card earlier the same day, in the Ireland v Australia match. Ireland's Rory Telfer had been given his marching orders after poor tackle technique resulted in a cringe-worthy head-on-head collision. His penalty for the infringement of the law was then upgraded to red by the bunker.
Depending on the success of the current trial, it could be used in the World Cup warm-up matches for the senior sides, and even at the World Cup itself.
