Iran won their second Greco-Roman gold in two days after Omid Noroozi beat Georgia's Revaz Lashkhi in the -60kg category.
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.
Russia also won their second Greco-Roman wrestling gold in two days after Alan Khugaev beat Egypt's Karam Ebrahim in the men's -84kg final.
A significant number of Russians had packed the stands at the ExCeL Arena hoping to see Khugaev follow up Roman Vlasov's win in the -74kg division yesterday, and they roared with delight after seeing the 21-year-old overcome his opponent 1-0, 1-0.
Ebrahim had raised hopes of an Egyptian win after knocking out favourite Damian Janikowski in the semi-finals, but he could not deliver in a tight final which the Russian won after two par terres.
Poland's Janikowski made up for his semi-final defeat by claiming one of two bronzes available through the repechage.
Kazakhstan's Danyiel Gajiyev claimed the other bronze by beating Vladimer Gegeshidze in a controversial fight which saw the Georgian storm off and kick barriers after a decision went against him in the final round.