Wales v Australia saw a red card within the opening 15 minutes of the game after Wallabies No. 8 Rob Valetini left Welsh second-row Adam Beard sprawled on the turf.
The back-rower made head-on-head contact in a tackle against Beard, who was left with facial injuries and blood pouring from his face.
Referee Mike Adamson did not take long to come to the decision that a red card was warranted.
He told his assistants when analysing the incident: "Head on head, we have foul play, the player is at fault.
"Coming from distance and speed, high degree of danger".
Agreeing it was a sending off for the remainder of the game at the Principality Stadium, he added to the player: "It is high force. There's no mitigation."
Valetini was seen speaking to Beard as he exited the field, appearing to apologise, while Beard himself had blood seeping from his head as he himself exited for medical checks.
You can follow the match live here.
Sam Warburton, speaking as a pundit on Amazon Prime Video, said: "Valetini's not malicious, but it's really poor tackle technique."
Australia were leading 7-6 at the time, and Ben Carter replaced Beard for the remainder of the game.
Valetini is the sixth player to be red carded against Wales in 2021, following Ireland's Peter O'Mahony, Scotland's Zander Fagerson, France's Paul Willemse, Argentina's Juan Cruz Mallia and Fiji's Eroni Sau.
- Want the latest Welsh rugby news sent straight to you? Look no further.
