Brahim Diaz made his debut in Real Madrid’s 3-0 Copa del Rey last-16 first-leg victory over Leganes.
Spain youth international Diaz, 19, joined from Manchester City for £15m last week and appeared as a substitute with 12 minutes remaining.
Diaz replaced Vinicius Junior, who scored Real’s third, adding to Sergio Ramos’ penalty – his 100th career goal – and Lucas Vazquez’s strike.
The return leg takes place next Wednesday, 16 January (20:30 GMT).
Meanwhile, Antoine Griezmann scored the opener as Atletico Madrid were held to a 1-1 first-leg draw at Girona.
Getafe beat Real Valladolid 1-0, while Villarreal drew 2-2 with Espanyol.