Yang and Jung claimed the gold medal today at the Fairplex events complex in Pomona, a city in Los Angeles County, with an accumulative points score of 1,383 points.

Japan's Ayumu Saito and Taishu Sato finished in second overall on 1,371 points, while Elena Potapenko and Vladislav Sukharev of Kazakhstan completed the top three on 1,357.

For the second successive day, it was Japan who set off first in the decisive laser-run discipline,but Ayumu Saito and Taishu Sato were unable to match the running pace and shooting composure of Yang and Jung.

With the final lap approaching it looked like Great Britain's Jessica Varley and Myles Pillage might snatch an unexpected bronze medal out of the grasp of the Kazakh duo of Elena Potapenko and Vladislav Sukharev, but a 9sec shoot by Sukharev eliminated their challenge and ensured an all-Asian top three.

Earlier in the day, Potapenko and Sukharev narrowly defeated Varley and Pillage in the swimming with a time of 1min 59.38sec at the Claremont Club.

Varley and Pillage took second in 1:59.60, while the Koreans completed the swimming in 2:00.76.

There was no such competition in the fencing arena, though, as Japan's Saito and Sato dominated proceedings.

They scored an impressive tally of 30 victories and four defeats,and it was only in the bonus round where they lost the final series to Poland's Anna Maliszewska and Szymon Staskiewicz that their dominance was interrupted.

Maliszewska and Staskiewicz took second with 26 wins and 16 defeats while the Koreans completed the top three with a record of 24 wins and 18 defeats.

Poland's momentum did not last long as Staskiewicz endured a messy riding display that put the two individual Rio 2016 Olympic representatives out of contention.

It was Yang and Jung who enjoyed the smoothest experience on horseback, incurring only six penalty points.

Saito and Sato took second in the riding while Hungary's Anita Strobl and Istvan Malits finished in third place.

"The first mixed relay of the season was a success, specially for Asia as Korea won the gold medal, followed by Japan and Kazakhstan," said UIPM President Klaus Schormann.

"It was such an achievement for the Asian nations.

"We have seen here once more a great demonstration of team spirit and this makes us very confident to include the mixed relay event at Tokyo 2020."

The next stop on the World Cup circuit is due to be in Egyptian capital Cairo between March 24 and 26.