Alcorcon upsets Espanyol in Spanish Cup
Last-place Real Betis set aside its Spanish league woes with a 1-0 first-leg win over Athletic Bilbao in the last 16 of the Copa del Rey on Wednesday.
Castro headed home Juanfran Moreno's long cross at the far post in the 42nd minute for the winner at the Benito Villamarin Stadium.
Cedric Mabwati and Joan Verdu came close as Betis controlled the first half before Athletic improved. Kike Sola marked his return from injury with the visitor's best chances, finding the post just before stoppage time.
Also, Dani Pacheco scored as second division Alcorcon continued its good run in the domestic cup competition with a 1-0 victory over Espanyol in their first-leg match.
Lionel Messi is expected to return from injury later Wednesday when Barcelona plays Getafe.