pièce de résistancepi‧èce de ré‧sis‧tance /piˌes də reziːˈstɑːns/ noun [singular] 
the best or most important thing in a series, which comes after everything else: 
The pièce de résistance was a stunning goal in the last minute of the match.
the best or most important thing in a series, which comes after everything else: The pièce de résistance was a stunning goal in the last minute of the match.