Team Melli was defeated against Japan 3-0 (25-19, 25-22, 26-24) in the competition underway in Rimini, Italy.
Amir Ghafour grabbed 15 points for Iran, while Ishikawa Yuki scored 18 points for Japan.
Vladimir Alekno’s side is scheduled to face Russia on Saturday.
The competition format is a single round robin pool with each of the 16 teams facing every other ahead of semifinals between the top four of the standings.
The semifinal winners will clash for the title, with the losers playing out for the bronze medal.
The tournament is being held within a secure 'bubble' with all hygiene protocols in place to ensure the health and well-being of all athletes, officials and staff throughout the competition.