The Bermudan missed the opening two legs of the series in Abu Dhabi and Gold Coast through injury, but made her return to action in Japan.

Duffy made a decisive move during the bike leg of the race, contested over the Olympic distance of a 1.5 kilometre swim, 40km cycling and 10km run.

The 29-year-old moved clear of the field with Britain’s Sophie Coldwell, with rain creating an additional challenge for the peloton.

They entered the final transition with an advantage of over a minute, but Duffy then pulled away during the run section.

The world champion crossed the line in a winning time of 1 hour, 56min and 18sec.

Coldwell was unable to hold on for second place, with the Briton being overtaken by Americans Katie Zaferes and Kirsten Kasper in the closing stages.

Zaferes ended as the runner-up in 1:58:09, with Kasper finishing a further 8sec back to claim the final podium spot.

Coldwell would eventually finish in fourth place, while New Zealand’s Andrea Hewitt ended in 23rd place in the standings.

Having won the opening two legs of the series, Hewitt has now slipped behind Zaferes in the overall rankings.

Spain’s Mario Mola made it back-to-back victories in the men’s series, following on from his triumph in Gold Coast.

The world champion was part of a 30-man leading group on the bike course, which include fellow Spaniards Fernando Alarza and Javier Gomez.

Britain’s Jonathan Brownlee had also looked likely to contest the victory, but a late crash in the cycling leg forced the Rio 2016 silver medallist to run to the transition, carrying his broken bike.

It ruled him out of contention, with Mola ultimately taking the race win in a time of 1:48:15.

Alarza ended as the runner-up after finishing eight seconds behind, while Norway’s Kristian Blummenfelt crossed the line in 1:48:26 for third.

Mola now leads the WTS series following his victory.