Regain, but not in time to get back at the race (7)
I believe the answer is:
regatta
'race' is the definition.
(I've seen this before)
'regain but not in time to get back at' is the wordplay.
'but not' is a deletion indicator.
'time' becomes 't' (abbreviation).
'to get back' shows that the letters should be reversed in order (I've seen 'got back' mean this).
'regain' with 'in' taken away is 'rega'.
'at' reversed gives 'ta'.
'rega'+'t'+'ta'='REGATTA'
'the' acts as a link.
(Other definitions for regatta that I've seen before include "Yacht-race event" , "E.g. Henley" , "Sporting event with boat or yacht races" , "Sports event" , "Boat festival" .)