Fighting over centre court sale (7)
I believe the answer is:
auction
'sale' is the definition.
(I've seen this before)
'fighting over centre court' is the wordplay.
'fighting' becomes 'action' (I've seen this before).
'over' means one lot of letters goes inside another.
'centre court' becomes 'u' (centre of the word 'court').
'action' enclosing 'u' is 'AUCTION'.
(Other definitions for auction that I've seen before include "event with lots involved" , "Caution about method of sale" , "Public sale with lots" , "Where things are sold to the highest bidder" , "A lot will be seen in this" .)