Where marathon winners make their name eventually (2,3,4,3)
I believe the answer is:
in the long run
'eventually' is the definition.
(I've seen this in another clue)
'where marathon winners make their name' is the wordplay.
I cannot quite understand how this works, but
'marathon' could be 'long' (marathon can mean long or lengthy) and 'long' is found in the answer.
'name' could be 'n' (common abbreviation e.g. on forms) and 'n' is present in the answer.
an anagram of 'their' is 'ither' which is located in the remaining letters.
The remaining letters 'un' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for in the long run that I've seen before include "ultimately - with 8d" , "sooner or later" , "marathon effort" , "At the end of the day" , "Where marathon competitors are seen" .)