Crowd-scene actor in run (5)
I believe the answer is:
extra
I believe this is a double definition.
'crowd-scene actor' is the first definition.
(I've seen this in another clue)
'run' is the second definition.
(cricket run)
'in' acts as a link.
(Other definitions for extra that I've seen before include "Spare" , "Studio crowd player" , "E.g. wide in cricket" , "Sundry" , "lesser player" .)