The Brazil international had been celebrating his 50th-minute wonder-goal when he was approached by Benfica's Gianluca Prestianni, who said something to Vinicius with his shirt over his mouth .
In a stunning intervention on social media, the Portuguese club shared a pitchside angle of the exchange, in which Prestianni can be seen in the vicinity of Vinicius.
Trent Alexander-Arnold calls the alleged racist abuse of team-mate Vinicius Junior a "disgrace to football", while opposition manager Jose Mourinho is criticised for his comments.