Ousmane Dembele delivered the cross for the Chilean, after showing fast feet to shimmy past Nacho in defence.
The youngster had far too much time to pick out the perfect cross, and substitute Vidal was making an incisive run into the area at the perfect time.
Vidal ran between Sergio Ramos and Marco Asensio, and he rose high to bury his header into the bottom of Thibaut Courtois' net.
The result leaves Madrid manager Julen Lopetegui in a precarious position, and it seems highly likely that his time with the club is over.
28 October 2018