Nascimento set a new mark of 57.58sec in qualification and then improved on that in the final with a time of 57.56.

Spain’s José Antonio Mari-Alcaraz won the silver medal in 58.10 and Brazil’s Ruiter Antônio Gonçalves Silva rounded out the podium with a time of 59.70.

Victory for Nascimento was one of many for hosts Brazil on the opening day of action at the Olympic Aquatics Stadium as they claimed six gold medals in all.

The aptly named André Brasil was another home favourite to shine, winning the men’s 100m freestyle S10 and men’s 100m butterfly S10 events.

Brasil clocked a time of 52.16 in the freestyle final as compatriot Phelipe Rodrigues came second in 52.61 and Argentina’s Bruno Lemaire finished third in 58.93.

In the butterfly, the 31-year-old touched home in 58.10 with Spain’s David Julián Levecq Vives coming second in 59.23 and Cuba’s Juan Castillo Estevez finishing third in 1:03.18.  

There were also home wins today for Andre Luis Meneghetti in the men's 100m butterfly S11 and Thomaz Rocha Matera in the men’s 200m medley SM13.

Meneghetti posted a time of 1:13.30, narrowly bettering the 1:13.57 of Colombia’s Leider Albeiro Lemus Rojas, who was 0.59 seconds quicker than third-placed José Luiz Perdigão Mai of Brazil.

Matera registered 2:23.46 to finish 14.86 seconds ahead of fellow countryman Alan Augusto Da Silva Santos and a further 13.19 seconds clear of bronze medallist Jonas Simone of Argentina.

Brazil’s one other gold medal came in the men’s 100m freestyle S11 final as Matheus Rheine Corrêa de Sousa won with a time of 59.23.

South Africa’s Hendrik Herbst was second in 1:00.43, while Japan’s Keiichi Kimura was third in 1:00.67.

Daniel Dias, Brazil’s 10-time Paralympic gold medallist, had to settle for the bronze medal in the men’s 50m butterfly S6.

His time of 36.66 saw him finish 5.59 seconds behind Colombian gold medallist Nelson Crispin Corzo, who was 3.31 seconds faster than runner-up Raul Alberto Martinez Valdes of Mexico. 

Action in Rio de Janeiro is set to continue tomorrow.