There are several synonyms for the expression "ran the show," including "controlled the operation," "managed the proceedings," "commanded the event," "directed the activities," and "presided over the affair." All these phrases convey the idea of being in charge and taking charge of the situation. To run the show implies that someone is ultimately responsible for organizing and leading the event, task or situation. Other synonym expressions that could be used include "took the helm," "led the charge," "steered the ship," "was the boss," all of which describe the act of taking control and establishing oneself as the key decision-maker.