Number two seed Diaz retained her title from 2018 - in an atmosphere at the Coliseo Mario Quijote Morales described as "electric" by the ITTF - with a 13-11, 11-8, 6-11, 11-9, 11-9 win over the top seed Zhang Mo from Canada.

Winning the first game was considered crucial for 18-year-old Diaz, giving her the confidence to take the second as well, before Mo threatened a fightback by taking the third.

In the end it was not to be for the Canadian as Diaz sank to the floor in emotion on winning the final point.

Earlier in the evening, Wu Yue from the United States beat Brazil's Bruna Takahashi in six games to win the bronze medal.

In the men's event top seed and defending champion Calderano took the title as expected.

It took the 22-year-old world number six player five games to see off Kanak Jha from the United States, 11-2, 12-14, 11-3, 11-8, 12-10.

"Kanak is very consistent, he has good control, he is young, playing on the World Tour and at World Championships," Calderano said.

"I have more experience than him but I'm sure that he can move to the next level.

"Today I felt confident in the serve and receive game, just sometimes I hesitated returning service and then I had problems."

Brazil also won the bronze medal in the men's event, as Gustavo Tsuboi - the number two seed - beat Marcelo Aguirre of Paraguay in five games 4-1.