Performance in contention is to go wrong (3,2)
I believe the answer is:
act up
'is to go wrong' is the definition.
(I've seen this before)
'performance in contention' is the wordplay.
'performance' becomes 'act' (act is a kind of performance).
'in contention' becomes 'up' (you can be 'in contention' or 'up' for an award).
'act'+'up'='ACT UP'
(Other definitions for act up that I've seen before include "Become unpleasant" , "Behave badly, give trouble" , "Behave badly, cause trouble - like thespian?" , "Informally, behave badly or cause trouble" , "Behave like a brat" .)