The duo begun the day 37 points ahead of Australia’s Jason Waterhouse and Lisa Darmanin and sealed their triumph by finishing second in the opening race of the day.

It ensured the rest of the day's competition, when they finished 10th in the second race and capsized in the last, did not matter.

Their lower results saw their tally move onto 59 points but Riou expressed her delight at sealing the victory with a day to spare.

“I called my family, and they were very happy,” she said.

“Right now this feels, weird, well no it feels, surreal.”

Denmark’s Allan Norregaard and Anette Viborg Andreasen now lead the chase for the silver medal having moved into second on 107 points, with Austria’s Thomas Zajac and Tanja Frank lying third on a total of 109.

One of the closest competitions in Florida has been the women’s 49erFX event, with the lead swapping hands again.

New Zealand’s Alex Maloney and Molly Meech had topped the standings after yesterday’s racing but the 2013 world champions recorded ninth, 11th and 17th place finishes to drop to fifth position.

London 2012 gold medal winner Tamara Echegoyen and her team-mate Berta Betanzos took full advantage as they secured a victory, as well as a second and third place, to move into the lead on 36 points.

The Spaniards, though, are just nine points ahead of Brazil’s Martine Grael and Kahena Kunze, while 54 points has proved enough for Italy’s Giulia Conti and Francesca Clapcich to lie third.

New Zealand’s Pete Burling and Blair Tuke look poised to win their fourth consecutive world title, despite finishing 20th in the second men’s 49er race of the day.

Their other results of second and fourth have given them a comfortable cushion of 28 points over Austria’s Nico Luca Marc Delle Karth and Nikolaus Leopold Resch, who currently have lie second on 65 points.

The duo can expect to come under pressure tomorrow from Denmark’s Jonas Warrer and Anders Thomsen for the silver medal, with only four points separating the teams.