Battle of the daft ring names or what? GGG v's Mack the knife? Not sure which is worse. Who thinks that **** up?
In Eastern Slavic naming customs (Golovkin is of Russian origin, like many Kazakhs due to it being part of the Soviet Union), you take your father's first name and add 'ovich/evich' for males, and 'ovna/evna' for females (called a 'patronymic, much like the second name system they have in Iceland with 'sson/dóttir'). His father was also Gennadiy, so he is Gennadiy Gennadievich Golovkin.
Indeed, a few more fights required perhaps (My GFs Mother, rest her soul, would have had me burn in hell for such a statement)