Simpson breaking bugger's back where fights occur (5)

'where fights occur' is the definition.
(a dojo is a hall for practising martial arts)

'simpson breaking bugger's back' is the wordplay.
'simpson' becomes 'OJ' (OJ Simpson).
'breaking' means one lot of letters goes inside another.
'bugger' becomes 'sod'.
'back' shows that the letters should be reversed in order.
'oj' inserted inside 'sod' is 'sojod'.
'sojod' in reverse letter order is 'DOJOS'.