Porto's Mali forward Moussa Marega said on Monday he 'couldn't stay on the pitch' after he suffered racist abuse in a Portugese league match at Vitoria Guimaraes at the weekend.
Marega, 28, walked off the field in disgust after being subjected to a torrent of monkey chants after scoring the winner in a 2-1 victory over his former club on Sunday.
"With all the insults I received, with the monkey chants targeted at me, I couldn't stay on the pitch," Marega told French radio station RMC.
"You can't stay like that and keep playing a match when people mock your skin colour."
In the 71st minute, Marega signalled to the bench he was leaving the pitch in protest even though teammates, Porto coach Sergio Conceicao and Vitoria players tried to get him to stay on the pitch.
"It was a huge embarrassment for me, it really effected me," Marega said.
"It started during the warm-up, but during the warm-up it was just three people.
"Three people shouting monkey chants and racist insults I think it happens to everyone in the world of football.
"When it's just three people you don't care. When it's a whole stadium, it's impossible to stay on the pitch."
Marega said he had a good relationship with Vitoria fans since leaving for Porto in June 2017.
"Every time I play against them, I applaud the supporters at the end of the match, I don't celebrate scoring, I respect them," he said.
Late on Sunday the French-born forward posted an angry message on his Instagram account.
"And also thank you to the referees for not defending me and for giving me a yellow card because I defended my skin colour. I hope I never find you on a pitch again. Shame on you," he added.