Real Madrid full-back Marcelo was subjected to racist abuse by Atlético Madrid fans after his side's 3-0 Copa del Rey semi-final first leg victory at the Santiago Bernabéu.
Marcelo was an unused substitute but joined teammates for a post-match warm down when Atléti fans - the only supporters remaining in the stadium - aired monkey chants at him.
They also sang: "Marcelo is a monkey," and when the Brazilian full-back's son came out to hug him they horrifically added "May your father die."
Journalists filing copy after the full-time whistle witnessed the atrocious behaviour, and the Spanish Football Federation will come under pressure to treat the incident seriously.
Brutal, horrible, disgusting monkey chants at Marcelo by the Atletico fans while he & the other Madrid subs do their warm down. Inexcusable— Graham Hunter (@BumperGraham) February 5, 2014
#Marcelo just turns and looks up at them in total disgust, puzzlement and bemusement at them. Hands on hips as if to say 'you clowns'— Graham Hunter (@BumperGraham) February 5, 2014