Iranian players Pouya Idani and Mohammad Amin Tabatabaie defeated their rivals in the first day of the event.
Idani defeated Bangladesh and Tabatabaie overpowered Yemeni rival.
Ehsan Ghaem Maghami tied with his Indonesian rival and will advance to next stage if he wins the second match.
Mobina Ali Nasab will have the chance to return the match if she wins the next competition.
Parham Maghsoodloo and Sarasadat Khademalsharieh are scheduled to participate in the second round.
The Chess World Cup 2021 is a 206-player single-elimination chess tournament that is underway in Sochi, Russia from July 12 to August 6 2021.
It is the 9th edition of the Chess World Cup.