The Iranian team, who had defeated Turkmenistan 6-3 in Group A of the Central Zone on Saturday, emerged victorious over Afghanistan 4-2.
Behdad Sheikh Ahmadi scored a hat-trick and Salar Aghapour was on target one time for Iran.
Iran advanced to the 2019 AFC U-20 Futsal Championship as the group winner.
Group B consists of host Uzbekistan, Tajikistan and Kyrgyzstan.
The top three teams book their places in the 2019 AFC U-20 Futsal Championship.
The 2019 AFC U-20 Futsal Championship qualification is the qualification process organized by the Asian Football Confederation (AFC) to determine the participating teams for the 2019 AFC U-20 Futsal Championship to be held in Iran.
Of the 47 AFC member associations, a total of 23 teams entered the competition. The qualification process is divided into four zones: ASEAN Zone, Central Zone, East Zone and West Zone (no teams from South Zone entered qualification).