Real Madrid fell to a narrow 1-0 defeat at the Mestalla, as Valencia gave themselves a significant boost in their quest to avoid the drop.
Real have already had a disappointing week, with them going out of the UEFA Champions League, while Barcelona took away their La Liga crown.
Diego Lopez gave Valencia the lead in the first half, yet the game was marred by late controversy,as Vinicius Jr was sent off in injury after appearing to catch Hugo Duro with a forearm in a clash.
The act was the result of the Brazilian growing increasingly frustrated by a number of alleged racist chants from the home crowd. Vinicius had already tried to bring a Valencia fan to the referee's attention earlier in the game.
He has since responded to the racism on display on social media, saying: 'It wasn't the first time, nor the second, nor the third. Racism is normal in La Liga. The competition thinks it's normal, the Federation does too and the opponents encourage it.'
'I'm so sorry. The championship that once belonged to Ronaldinho, Ronaldo, Cristiano and Messi today belongs to racists. A beautiful nation, which welcomed me and which I love, but which agreed to export the image of a racist country to the world,' he added.
'I'm sorry for the Spaniards who don't agree, but today, in Brazil, Spain is known as a country of racists. And unfortunately, for everything that happens each week, I have no defense. I agree,' he continued.
'But I am strong and I will go to the end against racists. Even if far from here,' Vinicius Jr concluded.
According to The Athletic's Mario Cortegana, Valencia sources have stated that should the facts about racist chants be confirmed on Monday, then the fans will 'get a ban forever'.
The controversy surrounding La Liga's work to curb racism, together with the negative environment that Vinicius has been surrounded by, have quickly prompted reports that he could be set to leave the club as a result.
However, ESPN Brasil have stated that while his entourage have taken the possibility of him leaving Real Madrid, he 'does not entertain this idea'.
This was also confirmed by Fabrizio Romano, who noted that he is 'absolutely not considering' leaving Real Madrid, as he wants to stay and 'beat racism in Spain'. Additionally, he has also recently signed a new long-term deal.
Real Madrid manager also took to social media to voice his displeasure at the way he was treated, saying: 'Today has been a sad day at Mestalla, where a group of fans have shown their worst version.'
'It is time to stop talking and act forcefully. Racism cannot have a place in football or in society. NO TO RACISM ANYWHERE,' he added.
Vinicius has had a good season individually, scoring 23 goals and providing 21 assists in all competitions, and Real Madrid fans will be ecstatic to hear that he is eager to stay at the club, despite the situation.