Wanheng made his eighth title defence with a fifth round stoppage victory in his homeland.
Estrada (16-3-0, 6 KO’S) came into the fight from defeating boxing maestro Mexican Saúl “Baby” Juarez in a stirring elimination match but was beaten by the better man.
Both warriors had breezed through the official weigh in at the Sami Thani Hotel in Khorat, Nakhon Ratchasima, each hitting the 105 pounds mark.
Meenayothin now has a record of 50-0, with 18 knockouts. So winning this historically equals Floyd Mayweather fabled half-century record.