He scored Iran’s fifth goal in a friendly match against Syria at the Azadi Stadium on Thursday.
His debut for Iran national team came as a sub in the 80th minute.
Sayyadmanesh found the back of the net at the age of 17 years and 342 days.
The record was previously held by Saeid Ezatolahi with 19 years and 40 days old.
Sayyadmanesh had already made headlines during the 2017 U-17 World Cup, scoring four goals and helping Iran make it to the quarter-finals.