Majestic Thunderbolt(1985)

Original title: Lei ting chu chuan

Two rival bosses of diamond smuggling outfits, Tiger and Franco, get into conflict over a very valuable diamond. Tiger is an apparently conventional businessman. Franco is a psychopathic playboy whose pride and lust know no limits and who murders his own mistress for her infidelity. It is smuggled into Hong Kong by Richard who tries to make a deal with Franco but Tiger hears about this deal and sends in Philip, a New York assassin, to steal the diamond.