Some events the Spanish hotel mounted in top-flight rooms? (9)
I believe the answer is:
athletics
'some events' is the definition.
(athletics sports events)
'the spanish hotel mounted in top-flight rooms?' is the wordplay.
'the spanish' becomes 'el' ('the' in Spanish).
'hotel' becomes 'h' (phonetic alphabet).
'mounted' shows that the letters should be reversed in order (in a down clue, letters mounted up).
'in' indicates putting letters inside.
'top-flight rooms?' becomes 'attics' (rooms at the top of a house).
'el'+'h'='elh'
'elh' reversed gives 'hle'.
'hle' put into 'attics' is 'ATHLETICS'.
(Other definitions for athletics that I've seen before include "Running and jumping" , "on the track, perhaps" , "Physical sports for trained competitors" , "Sports -- cheat list (anag)" , "Lithe acts performed in physical sports" .)