A Fantastic Woman is out now across United Kingdom cinemas.
"I hope this award, this film, and the awareness it has created, the amplifier that this means, helps to give more relevance to a matter that is urgent, because again, a transgender person is not a class B person".
In some ways, what happens when 20something Marina's (Daniela Vega) much older boyfriend, Orlando (Francisco Reyes), dies unexpectedly in their home is a familiar tale: His ex-wife and adult children - some of whom are probably older than Marina herself - rebel at the idea of his new partner attending the wake and funeral. They had shared a protective bubble of bliss and tenderness that is suddenly shattered and Marina's world falls apart.
When Lelio accepted the award on stage, he called Vega his inspiration for the film.
"Thank you so much, this is an fantastic gift", director Sebastián Lelio said, adding, "I want to thank the cast of the film, especially the brilliant actor Francisco Reyes and the inspiration for this movie, Daniela Vega". She became the first openly transgender presenter at an Oscar ceremony when she introduced a song during Monday's event.
The movie was initially about a cisgender character; however, Lelio was inspired to change the story after he began working with Vega, who initially joined the movie as a LGBT advisor.
"I was not going to make this film without a transgender actress in the main role", Lelio said backstage, adding that Vega brought a presence and truthfulness and complexity to the role that he didn't think a non-transgender actor could have.
"She carries that history and the camera knows that", he said.
Other nominees in the category was The Insult (Lebanon), Loveless (Russia), On Body and Soul (Hungary) and The Square (Sweden).
Moreno received a standing ovation when she took the stage.
Daniela, 28, has appeared in only one film before A Fantastic Woman.