Utterly exhausted, one breaking racket (4,2)
I believe the answer is:
done in
'utterly exhausted' is the definition.
(I've seen this before)
'one breaking racket' is the wordplay.
'breaking' means one lot of letters goes inside another.
'racket' becomes 'din' (I've seen this before).
'one' put into 'din' is 'DONE IN'.
(Other definitions for done in that I've seen before include "very tired" , "Spent" , "lacking strength" , "physically exhausted" , "Utterly exhausted" .)