Madrid: Real Sociedad ended the Copa del Rey hopes of second division Mirandes on Wednesday with a 1-0 win which moved them into the final for the first time in 32 years.
Sociedad had already won the first leg 2-1 and cemented their spot in the decider when striker Mikel Oyarzabal scored a 41st-minute penalty after a handball in the area by a Mirandes player.
The April 18 final in Seville could be an all-Basque affair with Athletic Bilbao defending a 1-0 lead against fellow La Liga mid-table side Granada in their semifinal second leg on Thursday.
Mirandes were attempting to become the first second division club to reach the final since 1980.
Real Sociedad, who were Copa del Rey winners in 1909 and 1987 and knocked out Real Madrid 4-3 in this season's quarterfinals, will be playing in their first final since 1988 when they lost 1-0 to Barcelona.
With 23 titles, Athletic Bilbao are second on the all-time list of Cup winners behind Barcelona who have triumphed 30 times.