The Iranian team had earlier defeated China, South Korea and India in the competition.
Iran will play winner of Chinese Taipei and Thailand in semi-final on Friday.
The 2018 Asian Men's U-20 Volleyball Championship kicked off on July 21, and will run through July 28.
The top two teams of the tournament will qualify for the 2019 FIVB Volleyball Men's U-21 World Championship as Asian representatives.