Following on from a bronze medal at the Villars IFSC World Cup in lead, Duffy won his second medal on the circuit and his first in the boulder discipline.

The Pan American champion and Tokyo 2020 Olympian was the only one of the six finalists to make it to the top three times over the four zones.

By making the top in the third and fourth rounds, he was able to secure the gold medal for the United States.

Lee Do-hyun from South Korea climbed to the top on his first and third rounds to take the silver medal in front of 2021 boulder season champion Japan's Yoshiyuki Ogata, the bronze medallist.

Chong Jong-won of South Korea was fourth after making the top on two occasions from three zone attempts, finishing in front of Koroko Fujii of Japan and Germany's Yannick Flohe.

Tomorrow's competition continues with the women's boulder final.