Spain's opening game (5)
I believe the answer is:
event
'game' is the definition.
(thesaurus)
'spain's opening' is the wordplay.
'spain' becomes 'e' (abbreviation for Espana).
'opening' becomes 'vent' (vent is a kind of opening).
'e'+'vent'='EVENT'
(Other definitions for event that I've seen before include "tournament" , "case" , "'Occurrence, occasion (5)'" , "Item in sports programme" , "Race contest; occasion" .)