Two men's and two women's weight categories were contested on the opening day with both finalists in each earning quota places for their countries.
Monica Pimentel-Rodriguez gained Aruba their historic spot in the women's under 49kg class, where she was a beaten finalist against Peru's Lizbeth Diez Canseco Verde, who also earned a Rio spot.
Aruba's achievement echoes similar feats achieved by Cape Verde and the Democratic Republic of Congo, who earned their maiden Olympic places at the African Qualification Tournament earlier this year.
The United States had the best of day one, with a gold and silver medal to earn two Olympic berths.
Steven Lopez won the men's under 80kg final, seeing off Moises Hernandez who collected a spot for Dominican Republic.
In the men's over 80kg final, Stephen Lambdin was beaten but earned a spot alongside Cuba's victor Rafael Alba Castillo.
The women's under 57kg glory went to Panama's Carolena Carstens, who was too strong for Doris Patino of Colombia.
Day two of the tournament tomorrow will see players battle it out for the remaining eight Olympic qualification places in the women's under 67kg and over 67kg, and the male under 58kg and under 68kg categories.
National selectors will have to confirm their athletes' places at the Games, with the final decisions due to be revealed on the World Taekwondo Federation’s website on July 18.