Germany's Henry Graf led the way on the transition from the 750 metres swim to the 20 kilometres cycle, with Britain's Daniel Dixon and Andrew Schellenberger of the United States staying in contention.

However, his two nearest challengers suffered falls on the bike, handing the impressive Graf a 35sec lead going into the final 5km run.

Calamity then struck Graf in the first kilometre of the run as he began to struggle, with Bellido the first to pass him.

The Spaniard had a lead of 20sec halfway through the run and completed a comfortable victory.

Bellido explained how his race had been carefully planned out.

"The race was so hard, there were a lot of good athletes out there," said Bellido,

"But many came down on the bike and we had to be careful and avoid them.

"I knew I had to go straight out of T2 and that was where I could win it and what I had been training for.

"I just want to say thanks to my family and coaches and I cannot wait to celebrate this with them."

Home favourite João Nuno Batista came through in second.

His brother Ricardo Batista won the men's race the last time the Championships was held two years ago in Lausanne in Switzerland, and the silver medallist was thrilled with his performance.

"My brother was world champion in Lausanne two years ago and on the last lap of that run [it] was very complicated but the legs were still there so I am very happy," Batista commented.

Dominic Coy of Britain rounded off the podium, staving off a challenge from The Netherlands' Mitch Kolkman who finished fourth.

The women's race at the World Triathlon Junior Championships is scheduled for tomorrow.