Atkinson timed 17 minutes 10 seconds in the 1.5 kilometre swimming section, three seconds behind fellow Australian Craig Walton and two behind Marko Albert of Estonia.

But Atkinson stormed to the top of the field in the 40km bike section with a time of 1:03:30 and kept the lead, although he was 12th fastest in the final 10km running section.

His combined finishing time was 1:53:27, beating Bevan Docherty of New Zealand, who finished in 1:54:13, and another New Zealander, Kris Gemmell, third in 1:54:26.

It was Atkinson's fifth victory overall in the World Cup series, all of them coming in Japan. As well as his three-in-a-row Ishigaki wins, he took the Ishigaki event in 2000 and the Makuhari triathlon in 2003.

Fernandes, from Portugal, won her first title in Japan and 15th overall in the World Cup series in 2:04:16, beating Australia's World Cup points leader Emma Snowsill, who finished in 2:04:34, and Debbie Tanner of New Zealand, third in 2:04:51.

Fernandes led the seven-woman front group in the swimming section, leaving three-time world champion Snowsill and Tanner in the second group almost a minute behind the Portuguese.

Snowsill and Tanner worked hard in the bike section and then quickly came together to spend most of the running section shoulder to shoulder.

But Fernandes spurted on a hill on the last lap of the running section to win.

The race was the second leg of the 15-round World Cup series, with the next round coming in Lisbon, Portugal, on May 6.