Despite being one of the powerhouses of Olympic wrestling, Iran had not won Olympic gold in the Greco-Roman discipline before London, but now they have two after Noroozi followed compatriot Hamid Soryan by winning at the ExCeL.
Noroozi was not quite at his best in the early rounds, but the 26-year-old world champion brought his best game to the arena for this evening's final, which he won 1-0, 1-0.
Noroozi used all his strength to successfully defended a par terre in the first period and then got behind his opponent in the second to earn the match-winning point.
The win gives further impetus to the Iranian Olympic squad, who will be confident of adding more medals to their tally during the Wrestling competition after a poor first week at the Games.
Earlier Russia's Zaur Kuramagomedov and Japanese wrestler Ryutaro Matsumoto both won bronze medals after beating Hasan Aliyev and Aimat Keispayev in the finals of the repechage.