In the match held at the Milliy Stadium in Tashkent, Uzbekistan, Sardar Azmoun found the back of the net with a right-footed strike in the 48th minute, Tehran Times reported.
Iran defender Hossein Kananizadegan was sent off in the 90th minute after receiving the second yellow card.
Earlier in the day, Oman defeated Kyrgyzstan 1-0 to finish in third place.
Iran had defeated Afghanistan 6-1 and Kyrgyzstan 5-1 in Group B.
Iran forward Mehdi Taremi scored six goals in the tournament and became the top goalscorer.
The 2023 CAFA Nations Cup is the first edition of the CAFA Nations Cup, the biennial international men's football championship of Central Asia organized by Central Asian Football Association (CAFA).
The event was held in Kyrgyzstan and Uzbekistan from June 10 to 20.
MNA/PR