15 across
Tennis
champion
finally
quit
hard
work
(5)
Tennis champion finally quit hard work (5)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
Right, so hard work at the end is your definition - graft or toil, that sort of thing. For the wordplay, "tennis champion" points you to GRAF, as in Steffi Graf, and then "quit finally" just wants the last letter of "quit", which is T. Stick GRAF and T together and you've got your answer.