A subdued Fernando Torres has helped Atletico Madrid beat local rivals Real Madrid 2-0 in the first leg of their King's Cup last-16 tie.
Real finished last year on a 22-match winning run but lost to Valencia in La Liga on Sunday and they face a mountain to climb to turn the tie around in the second leg at the Bernabeu.
Raul Garcia scored from the penalty spot after 58 minutes after he was fouled by Sergio Ramos, and Jose Gimenez nodded in a corner 15 minutes from time.
The two clubs shared all the trophies available to them during 2014, but some spice was taken out of the derby with many players rested including Real forward Cristiano Ronaldo.
Torres was very quiet in his first start since his return to his boyhood club before being taken subbed off after an hour.
The winners of the tie face Barcelona or Elche, who play their first leg on Friday morning.
Elsewhere, Denis Cheryshev gave Villarreal a 1-0 home victory over Real Sociedad in their first-leg match.