The present invention encompasses a golf ball having a diameter and being comprised of a core and a cover, wherein the core is further comprised of a fluid mass at the center of the ball, and a first, solid, non-wound mantle layer surrounding the fluid mass, wherein the first mantle layer comprises a copolymer or terpolymer of ethylene and an a,.beta.-unsaturated carboxylic acid, the acid being neutralized at least 80% by a salt of an organic acid, a cation source, or a suitable base of the organic acid, and wherein the cover comprises polyurethane, polyurea, or a polyurea/polyurethane hybrid. Preferably, the rate of spin decay is at least 10% of an initial spin rate of the golf ball over the entire ball flight.