A super-tough polymeric composition comprising an engineering thermoplastic and a modified radial polymer. The engineering thermoplastic is selected from the group consisting of polyamides, thermoplastic polyesters, polyphenylene ether resins, polyarylene sulfide resins, polysulfone and the like. The modified radial polymer is modified by grafting a compound containing a carboxylic acid or carboxylic acid derivative group. The modified, radial polymer has from about 3 to about 50 arms, as determined using light scattering techniques and the arms will be olefin polymers. The polymer compositions will yield shaped articles which fail ductilely when tested using ASTM procedure D-256 at room temperature and some at -20.degree. F.