Yousefi seized a gold medal at the boys' +85kg event at the 2018 Summer Youth Olympics at the Parque Polideportivo Roca.
The Iranian representative lifted 162kg in snatch and 218kg in clean and jerk and won the gold medal with a total of 380.
Hristo Hristov from Bulgaria claimed a silver with a total of 379kg and Enzo Kuworge from the Netherlands took the bronze with 365kg.
Weightlifting at the 2018 Summer Youth Olympics was held from 7 to 13 October.