Home hopes Daniel Dias and André Brasil each completed a superb week of action at the Rio 2016 Paralympic test event in the freshly opened Olympic Aquatics Stadium.
Brasil, a seven-time Paralympic gold medal winner across the Beijing 2008 and London 2012 Games, secured his fifth victory of the competition by winning the S10 50 metres freestyle.
"Our work is being done in blocks," he said afterwards.
"The first was last year in the World Championships and the Parapan American Games, then training at the end of last year.
“Now we have participated in this test event ahead of the European Open Championships next week in Portugal and then we throw almost everything at the Paralympic Games."
Ten-time Paralympic champion Dias was similarly dominant in winning gold in the S5 category.
It brought the Brazilian gold medal haul to 14 after the three days of racing, alongside 22 silver and 30 bronze medals.
In total, 212 athletes from 19 countries attended the International Open event.
"Swimmers are leaving today to Portugal for the European Open," added Brazilian Paralympic Committee President Andrew Parsons.
"We observed some marks here at the Open and there is nothing that scares athletes who have not reached the levels.
“Everything is on schedule and they will face a stronger competition now.
"All of this is to reach their peak performance in September.”