Our qualitative and longitudinal study depicts the successful post-acquisition integration of a German company within an Italian MNC as a sequence of both cooperative and conflictual power games. Building on longitudinal empirical evidence, the process of post-acquisition integration is conceptualized as the merger between two different institutional power fields each of them organized around a specific logic. The cognitive and practical role of relational metaphors - i.e. ‘honeymoon’ and ‘duel’ - in managing ambiguity along the integration process is taken into account. Our research contributes to the current debate between organizational studies and international management literatures and proposes a theoretical model connecting different power games and relational metaphors in processes of post-acquisition integration.