Take on extra risk with service, chasing succession of balls (9)
I believe the answer is:
overwrite
'take on extra risk' is the definition.
(as in overwriting insurance)
'with service chasing succession of balls' is the wordplay.
'with' becomes 'w' (abbreviation).
'service' becomes 'rite' (a religious service).
'chasing' says to put letters next to each other (some letters chase after others).
'succession of balls' becomes 'over' (cricket term).
'w'+'rite'='write'
'write' after 'over' is 'OVERWRITE'.
(Another definition for overwrite that I've seen is " add new characters to script?".)