Russian Artem Parienko and Poland's Marek Jaskolka claimed second and third place in the men's competition, recording their first ever World Cup medals, with Jaskolka's the first a Polish athlete had won in Triathlon history.

Riveros Diaz's took gold in the women's contest, following hot on the heels of her bronze at the first World Cup of the season in Mooloolaba, and she dominated after taking the lead on the run.

In taking gold, Kemper achieved his first World Cup win since 2005, after having finished second in Ishikagi in both 2005 and 2006, losing to five-time winner Courtney Atkinson, who was not competing this year.

Kemper is also the first American to win in Ishigaki since its inception in 1996.

"I was second in 2006 to Courtney Atkinson, and as you know he does well on this course, but it felt good to finally come through with a victory," Kemper said.

"It's my second race of the year, and it feels good to win in Ishigaki, it's a beautiful place.

"I've had injuries for the past two years - it's been very difficult since Beijing in 2008, and this is my first World Cup win in a while.

"It feels good to be back on top of the podium and win here in Ishigaki in front of the Japanese people, who have dealt with so much the past month or six weeks, it feels good to celebrate even if just for a few hours."

Jaskolka was similarly delighted with his performance

"After two years of sickness and injuries, I'm back.

"I'm really surprised that I got third here, it was such a strong field.

"Three weeks ago, I raced in Valparaiso for an Pan American Cup, and I applied the same strategy.

"I just stayed behind the other guys and waited for the last lap, because it's my strongest lap, and it worked out."

Parienko, who made his debut on the elite course in 2007, said: "The finish was very hard. I had to run much faster, and I was able to take second place."

It was cloudy at the start of the men's race in Ishigaki, the longest running World Cup in the history of the International Triathlon Union, with Russian brothers Ivan and Denis Vasiliev setting the early pace in the 1.5 kilometres swim, 40km bike and 10km run race.

Kemper, alongside Spain's Ivan Rana, caught the leaders at the start of the run before Kemper took the lead, from which point he never looked back, with the other podium places remaining tightly contested until the end.

Rana came agonisingly close as Parienko and Jaskolka outsprinted him in a thrilling finale.

In the women's race, Ireland's Aileen Morrison came second whilst defending champion Japan's Kiyomi Niwata took third with an impressive late surge.

Riveros Diaz said: "My victory is for everyone, giving love and happiness.

"I was a little tired from the last race, but have to be smart and manage myself to get to the finish line.

"The atmosphere was amazing, even if I wasn't Japanese, they were cheering me."

Unlike the men's race, the women's event started in near perfect conditions with Britain's Kerry Lang, Denmark's Line Jensen, Czech Republic's Radka Vodickova and Japan's Eri Kawashima setting the pace early on.

Morrison, Niwata, Erin Densham and Marina Damlaimcourt chased Riveros hard but never seriously threatened her lead.

Ireland's Morrison pulled away from the chasing pack late on, and she was thrilled to take silver.

"I am absolutely fantastic and delighted to stand on the podium," she said.

"A lovely place to do a race, in Ishigaki, with fantastic people, a fantastic course.

"It was really hard, yet loved it and am delighted I finished second."

Niwata edged out Damlaimcourt in the final sprint and paid tribute to the spectators.

"I didn't think of getting on the podium or winning the race.

"I was neck to neck chasing third place, but people were saying to me 'Get, podium! Get podium!'

"I think Ishigaki people love me a lot and look after me."

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