She finished comfortably clear of the American Olympic champion of 2016, Gwen Jorgensen, back racing after having two children, who took silver.

Luxembourg’s Jeanne Lehair earned her first World Cup medal of the season in third place.

The men’s race saw an emotional breakthrough victory for Britain’s Hugo Milner, who finished ahead of New Zealand’s Dylan McCullough and the fast-finishing German, Lasse Nygaard Priester.

Seregni headed a lead group of seven out of the water and made a perfect transition to the biking section, with Jorgensen in the chasing group 20 seconds back.

The American made up ground to become one of a leading five that included Lehair and Seregni as they moved into the final phase, from which the Italian emerged first.

Jorgensen, as she had in the previous World Cup event in Tongyeong, hit problems on this last transition and set off on the four-lap 10 kilometres course 15sec behind the leader.

By the closing stages, however, Jorgensen had moved up to challenge Lehair for second place.

The Italian finished clear in 1hour 59min 43sec, with Jorgensen taking second place in 2:00:01 ahead of Lehair, who clocked 2:00.10, with Seregni’s team-mate Alice Betto fourth in 2:00:19.

"This is my last race of the season," said Seregni.

"I’m so happy and I am so satisfied about my results, about this year."

Jorgensen added: "Bianca had an amazing race today.

"I don’t know if I could have run with her but I felt like I handed the win away with my T2."

Milner did not figure in the lead until the closing stages of a men’s race in which McCullough was in the lead group into the first transition.

The New Zealander maintained position in a group of 11 which became 10 when home athlete Takumi Hojo fell off his bike and was unable to continue.

By the fourth and final bike ride lap, however, the chasing group had moved up to create a bunch of 16.

Milner, who only started in triathlon two years ago and crossed the line in 52nd place last weekend in the World Triathlon Cup at Tongyeong, was well back as the final run began, but was able to move up steadily.

With five kilometres to go he was third behind last week’s World Cup silver medallist, Ricardo Batista of Portugal in second place and McCullough.

In the closing stages the relative newcomer found the acceleration to move past his New Zealand rival, finishing in 1:47:46, with McCullough four seconds behind and satisfied with his first World Cup medal.

Behind the Briton, Batista was overtaken by Priester and Canada’s Tyler Mislawchuk, who clocked 1:47:59 and 1:48:03 respectively, with the Portuguese runner taking fifth place in 1:48:04.