Real Union has ended Real Madrid Castilla's recent winning run.
The Real reserves were unfortunate in the Di Stéfano Stadium and saw their unbeaten run of eight games come to an end.
They dominated the game and created clear chances but were unable to mount a comeback in a match made difficult for them in the first half, when the Basque side made the most of one of the only goal-scoring opportunities it created.
Goikoetxeao headed home a cross from the left wing, proving the matchwinner for the Basques.
