The fuzz on the ball increases layer mixing within the boundary layer, producing a turbulent boundary layer (as opposed to laminar). Turbulent boundary layers have increased shear stress (which means increased skin-friction drag) but the increased mixing makes them more resilient to boundary layer separation. A boundary layer flowing within an adverse pressure gradient (a pressure gradient which increases with the direction of flow) will eventually separate, and the region past the point of separation has lower pressure than the surrounding air. If you can delay separation, you decrease the actuating area for the low pressure region to act upon, decreasing pressure drag. For small objects with low Reynolds numbers, the trade-off of increased skin friction drag for decreased pressure drag is usually beneficial.