Cast down in one attempt (5)

I believe the answer is:

abash

'cast down' is the definition.
(thesaurus)

'one attempt' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'attempt' becomes 'bash' (I've seen this before).
'a'+'bash'='ABASH'

'in' acts as a link.

(Other definitions for abash that I've seen before include "Discomfit" , "put one to shame" , "Bring shame on" , "Strike with embarrassment" , "Cause to feel ashamed" .)

I've seen this clue in the Evening Standard.

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