<p>The escape of farmed fish represents a critical anthropogenic disturbance in coastal marine ecosystems. The Hulong hybrid grouper (<i>Epinephelus fuscoguttatus</i>♀ × <i>E. lanceolatus</i>♂), a high-performance aquaculture species, has seen an increase in reported escapes in recent years with the rapid expansion of intensive aquaculture practices. However, their ecological interactions with native coastal groupers remain poorly understood. Here, we compared territorial competitiveness, feeding efficiency, and growth performance between Hulong hybrid grouper and two native nearshore groupers (<i>Epinephelus awoara</i> and <i>E. akaara</i>). The results showed that hybrid groupers exhibited an advantage in aggressiveness and territorial dominance, likely attributed to their parents' genetics and further enhanced by aquaculture conditions. Additionally, Hulong hybrid grouper also demonstrated superior acclimattization when transitioning from farmed to wild feeding regimes, with significantly higher feeding rates and efficiency than native species. These advantages facilitated survival and growth dominance in mixed populations, which will bring about potential ecological risks to native groupers. This study provides the first empirical evidence of the potential ecological risks to coastal marine ecosystem by escaped Hulong hybrid grouper from aquaculture facilities. It also highlights the urgent need to improve aquaculture management strategies.</p>