• Firm-SC sustainability relationship depends on firm size. • SC economic sustainability doesn't affect SMEs' economic sustainability. • SC environmental sustainability enhances SMEs' environmental sustainability. • SC social sustainability positively influences SMEs' social sustainability. The prior literature has predominantly emphasized the role of large firms exerting coercive power within supply chains to enhance sustainability outcomes. However, small and medium-sized enterprises (SMEs) often experience a reverse dynamic in which external pressures from supply chain agents drive sustainability initiatives. Drawing on Institutional Theory and Stakeholder Theory, this article examines whether supply chain sustainability improvements positively affect SMEs' economic, environmental, and social performance. Using a time-lagged research design, data were collected from a sample of 363 food and beverage manufacturing SMEs and analyzed using Structural Equation Modeling (SEM). The results provide support for the hypothesized relationships in the environmental and social dimensions of sustainability but not in the economic dimension. This implies that improvements in the social and environmental performance of the food and beverage manufacturing supply chain can positively influence SMEs' social and environmental performance, respectively. The article concludes with practical insights for managers, policymakers, and society at large on how to improve sustainable performance in food and beverage manufacturing SMEs.