This study explores the interplay between school leadership management, instructional leadership, and infrastructure readiness in driving teaching–learning transformation in secondary education within the Sustainable Development Goal 4 (SDG 4) framework. A qualitative case study approach was employed, with data collected through semi-structured interviews, non-participant observations, and document analysis involving principals, teachers, and administrative staff. Thematic analysis with open, axial, and selective coding was applied to identify patterns among key variables. The findings reveal that educational transformation emerges from the dynamic synergy between POAC-based school management, instructional leadership, and infrastructure readiness. School management aligned with instructional goals serves as a structural driver of pedagogical improvement, while instructional leadership mediates management strategies into classroom practices, fostering teacher agency and student-centered learning. Infrastructure readiness functions as both enabler and constraint depending on its strategic utilization. Although limited to a single-case context, the study offers actionable insights for policymakers and school leaders, emphasizing context-sensitive strategies in resource-constrained environments. It contributes an integrative, process-based framework connecting POAC management, instructional leadership, and infrastructure readiness within the SDG 4 agenda, bridging the gap between management and pedagogy for operationalizing quality education at the school level.