The number-five ranked competitor defeated world number one and 2014 world champion Davor Stefanek of Serbia in the semi-finals before overcoming Ryu 4-1 in the gold medal match.

He succeeds compatriots Alfred Ter-Mkrtychyan and Thomas Zander, who won at 52kg and 82kg gold respectively at the 1994 World Championships in Tampere, Finland. 

Stefanek recovered from his last-four exit to beat Algeria's Tarek Aziz Benaissa in the first bronze medal match.

He was joined on the third step of the podium by Russia's Artem Surkov, who controversially overcame Armenia's Migran Arutyunyan in an ill-tempered bout.

The second of three Greco-Roman finals on the opening day of action went the way of Surkov's countryman Roman Vlasov, defeating Denmark's Mark Overgaard Madsen 6-0 in the 75kg final having seen off 2014 world champion Arsen Julfalakyan of Armenia in the earlier rounds. 

"I cherish this medal more than the gold medal I won in London," said Vlasov, the 2012 Olympic gold medallist. 

"I went through so much trouble the last couple of years, but in everything I have persevered, fought and won."

Andrew Bisek, the Toronto 2015 Pan American Games gold medallist, secured hosts United States their first medal of the Championships with bronze at the expense of Iran's Saeid Abdvali.

The other third-place honour went to Kazakhstan's Doszhan Kartikov to the disappointment of Azerbaijan's Elvin Mursaliyev. 

The last final of the evening came at 98kg as Armenia's Artur Aleksanyan successfully defended his title, condemning London 2012 gold medallist Ghasem Rezaei of Iran to silver with a 3-0 triumph.

Romania's Alin Alexuc Ciurariu lost out to Ukraine's Dimitriy Timchenko in the second bronze medal match after Russia's Islam Magomedov, the Baku 2015 European Games gold medallist, had denied Bulgaria's Elis Guri a podium place in the first. 

The action in Las Vegas is set to continue tomorrow with the Greco-Roman competitions at 59kg, 71kg, 80kg and 130kg. 


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