Points out one success (3)
I believe the answer is:
win
'success' is the definition.
(I know that win is a type of triumph)
'points out one' is the wordplay.
'points' becomes 'wn' (two compass points).
'out' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'wn' going around 'i' is 'WIN'.
(Other definitions for win that I've seen before include "Gain; triumph" , "Come first" , "Finish in first place" , "Achieve victory" , "Come out on top" .)