Real Sociedad defeated Mirandes in the first-leg of their Copa del Rey semifinal on Thursday night.
Mikel Oyarzabal opened the scoring from the penalty spot, but the Segunda Division side would answer through Matheus.
However, La Real would regain a lead they would never relinquish through the Real Madrid loanee, giving the Basque side a small advantage heading into next month's return leg.
The final 20 minutes were a tight, intense affair, with Mirandes content to waste time but still willing to move forward and create chances, while La Real were keen to tack on an insurance goal before the final whistle.
The best chance came in the final seconds of stoppage time when Mirandes midfielder Jon Guridi, another player on loan from La Real, almost headed in an own goal off a free-kick. In the end, the two teams would settle for the 2-1 final, leaving their semi-final tie wide open going into the second leg at the Estadio Municipal de Anduva.