This study investigates the key social, psychological, and technological factors influencing social commerce adoption among Gen Z university students in Vietnam. It examines how social support constructs, trust, and technophilia contribute to forming social commerce intention and translating it into actual usage behavior. Guided by the Stimulus-Organism-Response model and the Theory of Planned Behavior, a survey was conducted with 757 Gen Z university students in Vietnam. The study employed Partial Least Squares Structural Equation Modeling using SmartPLS 4.0.9.2 and IBM SPSS 27 were used to analyze descriptive statistics and test direct and mediated relationships. The study revealed that information support, social interaction, trust, and technophilia significantly influence social commerce intention, while emotional support and subjective norms indirectly affect intention through trust. Trust also directly predicts actual usage behavior. Technophilia emerged as both a direct predictor and a moderator of the intention-behavior link, addressing the intention-behavior gap in social commerce literature. This research is among the first to integrate actual usage behavior and technophilia into a comprehensive social commerce adoption model in an emerging market context. It offers novel insights into how trust mediates social influences and how technophilia moderates the relationship between social commerce intention and actual usage behavior, contributing to theory and practice in adopting digital commerce.