It's a remarkable achievement considering how close he was to an opening round exit in Oslo.
The 25-year-old was 6-1 down to Japanese grappler SHIMOYAMADA Tsuchika and facing a shock early departure, but turned it around and went all the way to the top of the podium.
The reigning 67kg Olympic champ from the Tokyo 2020 Games in 2021 is now a World champ too, achieving legendary status among Iran's wrestling fans and beyond.
Geraei wasn't the only Iranian wrestler celebrating on Sunday, as 24-year-old Meysam Dalkhani topped the podium in the 63kg category.
It was Dalkhani's first World title too, as the U23 champion stepped up on the World senior stage and proved his talent with a 5-2 victory in the final over Georgia's Leri Abuladze.
It rounded off a hugely impressive showing from the Iranian wrestling team, who were dominant throughout this tournament with a wealth of young stars on the rise.
And in the final event of the Oslo '21 Worlds, Serbia's Zurabi Datunashvili defeated 23-year-old Kiryl Maskevich of Belarus by 9-1.
Datunashvili adds his World gold to the Olympic bronze medal he won at the Tokyo Games.