Hold spellbound during tenth rally (7)
I believe the answer is:
enthral
'hold spellbound' is the definition.
(I've seen this before)
'during tenth rally' is the wordplay.
'during' says the answer is hidden in the clue.
'ENTHRAL' is hidden within 'tenth rally'.
(Other definitions for enthral that I've seen before include "Beguile" , "absorb" , "Bewitch" , "Fascinate - grip" , "Totally fascinate" .)