The duo finished in sixth place overall, but that proved good enough to claim the sole spot as all five teams to finish above them were all representing South Africa. 

Asenathi Jim and Roger Hudson claimed the gold medal with 17 points on their home waters at Granger Bay in Cape Town.

Compatriots Sibusiso Sizatu and Alex Burger finished second on 27 points while Brevan Thompson and Alexander Ham ended up third on 31.

With Jim and Hudson have already qualified at last year's World Championships and each country only permitted one spot, it was left to a battle between pairs from Angola and Algeria.

This was won by Montinho and Afonso with 55 points, with Algerians Hakim Djoulah and Samir Ksouri finishing down in 10th with 119.

Yet the Angolan duo are not yet guaranteed to compete in Rio de Janeiro's Guanabara Bay in August, because compatriots Francisco Artur and Edivaldo Torres finished eighth and could still be selected ahead of them.

Whoever is chosen will follow the trail blazed by Eliseu Ganda and Luvambu Filipe, who finished in 37th place in the men's 470 event at Barcelona 1992.

"It's a very important achievement, mainly for all the efforts from the various parties involved, sailors, clubs, coaches over the last eight years' programme," said Nuno Gomes, vice-president of the Angolan Federation of Nautical Sports

"It makes us believe it's possible, as the 1992 Olympics participation was more of an invitation.

"This will make kids dream, and adults believe…and old people remember."

Both teams will now return home to train ahead of a decision being made "on merit" as to who will be put forward.