The 31-year-old fighter from Louisiana in a fight in the weight category up to 69.9 kg defeated Argentine Brian Castaño by technical knockout in the tenth round.
The fight took place in Carson (USA, California).
Charlo has 35 wins (19 by KO), one loss, one draw.
He defended the WBC belt for the third time and the IBF and WBA for the second time.
Earlier, former WBC world heavyweight champion Grigory Drozd called Floyd Mayweather the favorite to fight Don Moore.