Marega, a French-born Mali international who had previously played for Vitória on loan in 2016/17, scored what proved to be the winning goal in the 60th minute.
The 28-year-old celebrated the goal by pointing at his skin in response to a section of the home fans who had targeted him throughout the match.
He was sadly shown a yellow card for his celebration and after the abuse continued, Marega attempted to leave the pitch and had to be physically restrained by teammates.
But Marega eventually shrugged off their efforts, and gave the Vitória fans a thumbs down as he headed to the changing rooms.
His reaction to the abuse has been praised by the Portuguese press, with A Bola newspaper giving Marega a perfect 10 rating in its player ratings.
Speaking to French radio station RMC, Marega said:
With all the insults I received, with the monkey chants targeted at me, I couldn't stay on the pitch.
You can't stay like that and keep playing a match when people mock your skin colour. I really felt like shit, it was a huge embarrassment for me, it really effected me.
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 later posted an angry message on his Instagram page, calling the fans who insulted him "idiots".
I just wanted to tell the idiots who go to stadiums to shout racist abuse... f**k you.
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.
Liga Portugal, the Primeira Liga's governing body, said they would take action in a statement.
Liga Portugal does not agree and never will with acts of racism, xenophobia or intolerance that jeopardise the dignity of footballers or any human beings.
Liga Portugal will do everything to ensure that this episode and all other racist incidents do not go unpunished.
We believe this is a fight where your team's colours do not matter and everyone must come together to eradicate this scourge on the game.