Yazdani defeated his tough American rival David Taylor 6-2 in the final of 86kg.
This big win saw the Iranian freestyle wrestler break a three-game losing streak against the American.
Taylor had defeated Yazdani in the Tokyo Olympics this past summer and also in the 2017 Wrestling World Cup in Kermanshah and 2017 Wrestling World Cup in Iowa City, the United States.
Yazdani on Saturday won his first match in the World Wrestling Championship 2021 in Oslo, Norway 12-2 against an opponent from Kazakhstan in less than 3 minutes.
Also, earlier on Saturday and on the second day of the championship, four other Iranian wrestlers became finalists to face their opponents on Sunday.