Favour running to ground (4,4)
I believe the answer is:
good turn
'favour' is the definition.
(good turn is a kind of favour)
'running to ground' is the wordplay.
'running' is an anagram indicator (the letters run around to different places).
'to'+'ground'='toground'
'toground' with letters rearranged gives 'GOOD TURN'.
(Other definitions for good turn that I've seen before include "Helpful deed" , "star performer" , "Nice act" , "Helping hand" , "Favour expected" .)