Karim Benzema faltered in front of goal, while the returning Ferland Mendy made a crucial mistake to see Real Madrid drop their fourth away fixture in a row, losing 1-0 against a Valencia side looking to avoid the drop.
Madrid looked every bit a team with nothing to play for. Although Los Blancos pieced some neat passages of play together early, they never created anything concrete. Valencia played their part, though, cutting an organised unit while needing at least a point to move four points clear of the drop zone.
And they found the net when given a rare opportunity. Mendy fell asleep at the back post, allowing Diego Lopez to sneak in and score the opener in his second career start.
Madrid made some introductions after the break, bringing Toni Kroos, Luka Modric and Rodrygo into the fold. The trio struggled to make an impact against a compact Valencia back-line, though.
But their efforts were rendered meaningless in a game paused by apparent racist abuse directed at Vinicius Junior. The referee halted play after the Brazilian winger singled out a fan in the stands, while a message in the stadium threatened to suspend the fixture if jeers continued.
Things spiraled out of control after, with Vinicius shown a straight red card for slapping Valencia substitute Hugo Duro.
And after 14 minutes of stoppage time following a second half marked by ugliness and controversy, the home side held on for a 1-0 win.
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