Zinc phosphate impregnated graphite (Zn-IG) exhibits excellent lubricating properties; however, its long-term durability as a sacrificial, low-shear layer remains a critical challenge. This demonstrated that reducing the surface roughness from the micrometer to the nanometer scale can decrease the wear rate of Zn-IG from ∼0.31 × 10 -3 mm 3N -1m -1 to ∼0.07 × 10 -3 mm 3N -1m -1, a reduction of approximately 77%. This improvement in surface precision mitigates abrasive wear and then maintains low local contact stress at the steel ball interface throughout the process. Consequently, it suppresses zinc phosphate precipitation, prevents atomic-scale damage to the graphite structure, and promotes the formation of a denser, more stable transfer layer on the steel counterface. These mechanisms collectively enhance the tribological performance of Zn-IG, providing a valuable basis for optimizing graphite-based friction materials and advancing their industrial applications.