Promoted team relegated - that's topsy-turvy (6-4)
I believe the answer is:
'topsy-turvy' is the definition.
'promoted team relegated' is the wordplay.
'promoted' becomes 'up' (I've seen this in other clues).
'team' becomes 'side' (both can mean a sports team).
'relegated' becomes 'down' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'that's' acts as a link.
Can you help me to learn more?