The duo had enjoyed a comfortable overnight lead in the competition, but struggled in the wind on the first of three races contested today.

It saw Grael and Kunze finish in 14th place in the 16-boat fleet, but they recovered to earn second and fourth place finishes in the remaining two races of the day to shore up their position.

"It was crazy,” Kunze reflected about the wind in the first race.

"It was going to the left and to the right, changing all the time.”

The Brazilians were able to discard their 14th place as their total points for the regatta moved onto 33, giving them a 17-point cushion over second placed Ragna and Maia Agerup of Norway ahead of the medal race.

Greal and Kunze can only be denied the World Cup victory should they finish last in tomorrow’s double point medal race, coupled with the Norwegians ending in first place.

Britain’s Dylan Fletcher-Scott and Stuart Bithell are already assured of victory in the men’s 49er class, despite finishing in 16th and 20th places in two of their races today.

The duo have an unassailable lead of 21 points over second place Benjamin Bildstein and David Hussl of Austria.

Further British success is on the cards in the Nacra 17 event, with Ben Saxton and Nicola Groves topping the standings on 35 points after three victories and one second place.

Their compatriots Tom Phipps and Nicola Boniface are in second place, with the duo having a tally of 44 points.

The men’s RS:X event has been won by France's Louis Giard after a run of five straight top-two finishes saw him open up a 33-point lead over his compatriot Pierre Le Coq ahead of the medal race.

China’s Yunxiu Lu is poised to earn victory in the women’s fleet, but Spain’s Marina Alabau Neira closed to 14 points after a strong sequence of results.

The finn, 470s, laser and radial classes will all race a full programme of races tomorrow, with their medal races scheduled to take place on Sunday (January 29).

Jorge Zarif leads the men’s finn fleet with three races left to contest, as the Brazilian has a total of 11 points to date.

He is 12-points clear of second place Ben Cornish of Britain, while Norway’s Anders Pedersen is a further four points adrift.

Heading into the final two days, France’s Jean Baptiste Bernaz holds a 32-point advantage over Pavlos Kontides of Cyprus in the laser class, while the women’s laser radial sees France’s Mathilde de Karangat hold a four point advantage over Belgium's Evi Van Acker.

The United States’ Stu McNay and David Hughes head the men’s 470 class by four points, with Panagiotis Mantis and Pavlos Kagialis of Greece occupying second place.

Afrodite Zegers and Anneloes van Veen of the Netherlands hold the women’s 470 lead, with Britain’s Sophie Weguelin and Eilidh McIntyre four points down.