Late money on - completely on target (4,6)
I believe the answer is:
dead centre
'completely on target' is the definition.
I know nothing about this answer so I can't tell whether this works.
'late money on' is the wordplay.
'late' becomes 'dead' (similar in meaning).
'money' becomes 'cent' (eg denomination of dollars).
'on' becomes 're' ('on' can be mean 'with reference to').
'dead'+'cent'+'re'='DEAD-CENTRE'
Can you help me to learn more?
(Other definitions for dead centre that I've seen before include "Position when engine crank and connecting-rod are in line" , "cemetery?" , "bullseye" , "Smack in the middle" , "Right in the middle" .)