Metabolically robust C-glycosides are crucial in various biological and medical applications, underscoring the need for efficient synthesis methods. While radical C-glycosylation reactions are known for their reliability and functional group tolerance, challenges such as glycosyl donor stability and atom economy persist. In this study, we investigate the underexplored potential of condition-controlled divergent synthesis of C-glycosides through a switchable photocatalytic C-glycosylation strategy, involving reductive anomeric C─O bond cleavage. Utilizing simple, readily available, and bench-stable glycosyl benzoates as novel O-based glycosyl radical precursors, we successfully achieve deoxygenative glycosylation of simple alkenes and styryl boronic acids, establishing a versatile platform for C-glycoside synthesis. A critical aspect of the challenging reductive cleavage of these benzoate esters is the introduction of strong single-electron transfer (SET) reductants, combined with Brønsted acids to accelerate fragmentation following substrate reduction. Notably, CO