A golf ball comprising a core, an intermediate layer, and a cover layer; wherein the intermediate layer is formed of a polymer blend comprising an ionomer having at least about 16% acid groups and a grafted-metallocene polymer; and the cover layer comprises a castable reactive liquid material. Optionally, a non-ionomer may be blended with the polymer blend or, in an alternative, the high acid ionomer may be blended solely with the non-ionomer.