United came out on top, you say (3)
I believe the answer is:
one
'united' is the definition.
(as in a phrase like 'we are one')
'came out on top you say' is the wordplay.
'came out on top' becomes 'won' (I've seen this in another clue).
'you say' shows a homophone (sound like).
'won' sounds like 'ONE'.
(Other definitions for one that I've seen before include "Lowest cardinal number" , "both halves" , "Sole; identical" , "Unit" , "United" .)