This paper examines the relationship between perceived event quality and visitor loyalty in the context of a river-based sport tourism event. This study examines visitors at the Danube Regatta in Negotin, a small-scale sport-tourism event integrated into the international Danube International Regatta. Drawing on event quality and experience economy frameworks, the study analyses the effects of four dimensions of perceived quality-organizational arrangements, program and atmosphere, environmental care, and infrastructure on visitors’ loyalty, operationalized through revisit intention and recommendation. The authors collected data through an on-site survey of 217 event visitors during the 2025 edition of the event. The analysis employed descriptive statistics, Spearman’s correlation, multiple linear regression, and cluster analysis (K-means). The results show that program and atmosphere represent the strongest predictors of visitor loyalty (β = 0.734, p < 0.001), confirming the dominant role of experiential elements. Organizational arrangements (β = 0.196, p < 0.01) and infrastructure (β = 0.203, p < 0.01) also exert statistically significant positive effects, suggesting their role as supporting conditions rather than primary drivers of loyalty. In contrast, perceived environmental care has a statistically significant negative effect (β = −0.240, p < 0.01), indicating a potentially complex sustainability-related relationship whereby perceived shortcomings in environmental practices reduce loyalty intentions. Cluster analysis identified four distinct visitor segments, highlighting heterogeneous visitor behavior motives and behavioral patterns among event participants. The findings add to the existing literature by providing empirical support for a multidimensional event quality–visitor loyalty framework in the context of small-scale river-based sport events. The study highlights the primacy of experiential components while emphasizing the need for more visible and effective environmental management practices in nature-based events.