Running through from behind, which is not playing fair (8,2,3,4)

'is not playing fair' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'running through from behind' is the wordplay.
I cannot really see how this works, but
'through' could be 'in' and 'in' is found in the answer.
'from' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
'behind' could be 'back' (similar in meaning) and 'back' is located in the answer.
This explanation may well be incorrect...

'which' is the link.

Can you help me to learn more?