The 22-year-old boxer from the United States won an early victory over former world champion and mandatory challenger Srisaket Sor Rungvisai from Thailand in a bantamweight bout.
Rodriguez in the seventh round knocked down the Thai boxer, and in the eighth the referee decided to stop the fight.
The fight took place in San Antonio (USA).
Rodriguez claimed the vacant title in February 2022 after defeating former world champion Carlos Cuadras of Mexico.
Earlier, the former absolute world boxing champion Konstantin Tszyu commented on the boxing sparring between Olympic figure skating champion Alina Zagitova and boxer Oleg Saitov.