It means the country have won all nine gold medals available at the competition in the Duna Arena, repeating their feat from the last World Championships, though that time around only five golds were up for grabs.

In the mixed duet free final, which took place first, Alina Mantulenko and Mikhail Vasilez performed as juniors for the last time, so it was perhaps fitting that they took the gold medal.

Their score of 85.1333 was enough for them to win by four points, with the Chinese pair of Haoyu Shi and Yiyao Yang taking the silver medal.

Japan’s pair of Jimma Iwasaki and Kana Miyauchi won the bronze medal with 80.7667 points.

"Such an honor to win both first gold medals in the history of mixed duet events at the Junior Worlds," Olga Brusnikina, the triple Olympic gold medal who was the choreographer of the programme and is vice-president of the Russian Synchronised Swimming Federation, said.

Brusnikina added: "We are shaken and touched. 

"We had a lot of concerns regarding the duo, as they started to train together less than one year ago."

Russia and Japan also took gold and bronze respectively in the women’s team free event, but the silver went to Ukraine.

Indeed while Russia took all the gold medals of the competition, the nine silvers and bronzes were all shared out between China, Japan and Ukraine.

Russia sealed the final gold medal of the event with 94.2333 points, while 92.1000 was enough for Ukraine to take the silver.

Japan, meanwhile, managed to take the bronze with 90.5333 points.