Competitors raced across a 20 kilometre downwind course between Viana do Castelo and Esposende in the north of the country.

Rice crossed the line first in the men's race in a time of 1 hour 21mins 52.88sec.

Spaniard Walter Bouzan took second place, three minutes behind in 1:24:15.95.

Rounding off the top three was Australia's Mackenzie Hynard, who posted a time of 1:24:36.73.

Nixon then claimed a sensational double for the African country in the women's race with a dominant performance.

She finished in 1:34:54.53 to beat New Zealand's Teneale Hatton.

Hatton crossed the line in 1:37:22.84 while France's Angie Le Roux secured the bronze with her time of 1:38:20.15.

South Africa's Jenna Ward missed out on a second medal for her country as she she finished 35 seconds behind Le Roux in 1:38:55.48 to clinch fourth.

More than 250 paddlers from 20 countries competed with €20,000 (£17,600/$22,800) in prize money on offer.

Following this weekend's stage in Portugal, action will now turn to Tahiti before the World Cup comes to an end in Brest, France.

The season will then conclude with the World Championships in Hong Kong in November.

The event is scheduled for the weekend of November 18 and 19 alongside the Asian Championships, with both events including men's and women's races.