This study assesses the impact of Supply Chain Management Practices (SCMP) on the performance of manufacturing Small and Medium Enterprises (SMEs) in the burgeoning economy of Ghana, utilizing Supply Chain Performance (SCP) as a mediator. The study's theoretical underpinnings are based on resource-based and relational view theories. The comprehensive metrics for SCMP, SCP, and OP were derived from an extensive review of the authoritative literature. Questionnaires were administered to gather data from 454 participants. These data were analyzed using Partial Least Squares (PLS)-based structural equation Modeling (SEM). The analysis revealed that the three dimensions of SCMP - customer relationship, postponement, and strategic supplier relationship–significantly influence OP, whereas information sharing and logistics integration do not. Furthermore, the study found no mediation effect of the four mediators on the relationships among supplier relationships, postponement, customer relationships, and OP. However, all SCP dimensions fully mediate the relationships among logistic integration, information sharing, and OP. These findings imply that excellence in SCMP alone does not guarantee superior overall performance. The findings imply that investing in SCMP alone may not be sufficient to drive superior OP; however, SCP are crucial to fully realize the full potential of SCMPs in enabling   OP, especially in the context of SMEs. This study contributes to the existing SCM literature by examining how SCMPs and SCP facilitate OP in developing countries. The paper also advances the SCMP literature by theorizing and validating an important but rarely studied role of the SCP. Thus, this study extends our understanding of the mechanisms through which SCMPs affect OP.