American Jacob Varner
took gold in the men's 96kg freestyle final
with a 1-0 win over Ukraine's Valerii Andriitsev.
Former Commonwealth Games wrestler Non Evans:
"The Ukrainian had him on the run and did very well to defend his lead and stay in the area. When he didn't have the Iranian Reza Yazdani in the final, he knew this gold was there for the taking."
A bronze medallist at last year's World Championships, Varner wins a bonus of around £160,000 offered to American gold medallists by USA wrestling.
His chances were boosted when world champion Reza Yazdani withdrew from the semi-finals with a knee injury.
Georgia's Georgi Gogshelidze and Khetag Gazyumov of Azerbaijan took the bronze medals.
Varner was the second American winner in the wrestling following
Jordan Burroughs' success in the 74kg category.
The American got behind Andriitsev in the first period and did so again in the second to earn a narrow victory.
Egyptian Saleh Emara was disqualified
after arriving half an hour late for Sunday morning's qualification session.