The duo have been in utterly dominant form at the Sanya Serenity Marina in China and took a 26-point advantage into tomorrow's final race.

They finished seventh and third in the first two races to guarantee gold despite a discarded 10th in the third.

Maiwenn Jacquin and Enora Percheron, of France, currently lie second with 66 points.

Jasmin May Galbraith and Chloe Fisher, of Australia, currently sit four points back in third.

"We still can't believe that we have won," said Porro. 

"We feel incredible. 

"It has been a fantastic week, in particular the first day because we gained three first places in all three races.

"We knew we won it after the second race today, this week and event has been so important for us."

Three teams are still in contention for medals in the boy's 29er class.

Théo Revil and Gautier Guevel, of France, enjoyed two second-place finishes moved into a slender one point lead over Mathia Barthet and Alexander Franks-Penty.

They sit on respective totals of 62 and 63 points.

Slovenian duo Rok Verderber and Klemen Semelbauer, the leaders at the beginning of the day, slipped back to third on 69 points.

United States' Charlotte Rose holds a two point lead over Uruguay's Dolores Moreira Fraschini in the women's laser radial category.

Rose sits on 26 points compared with 28 points for Fraschini heading into tomorrow's finale.

Luciana Cardozo, of Argentina, remains a distant third on 56 points.