"I am very happy and proud what I did," she said. "We came here every day to compete and perform (well). Gymnastics is not an easy sport, it requires a lot from our body and mind.
"I was confident I was able to manage all of the pressure and I worked with my coach in order to achieve what we've done."
Andrade's 14.166 was just ahead of Simone Biles (14.133).
Biles' American teammate Jordan Chiles was third, scoring a 13.766 after a scoring inquiry lifted her from fifth to the podium.
It's the 11th Olympic medal for Biles, extending her record as the most decorated U.S. Olympic gymnast.
The Brazilian star tumbled a front layout full to full-in and a full-twisting double layout to open. She closed with a controlled double pike.
Andrade took her time coming off the podium, savouring the appreciation from the crowd. When the final scores flashed inside Bercy Arena, the 25-year-old artistic gymnastics star seemed stunned during an embrace with coach.
In the warm-up, Biles looked cautious.
She has been dealing with a strained calf injury throughout the Games and struggled through her signature triple-double (Biles II) in the moments before she competed.
"Obviously wasn't my best performances, but at the end of the day, whoever medaled, medaled and that's what's so exciting because you just never know with gymnastics," said Biles afterward. "So I'm not very upset or anything my performance at the Olympics. I'm actually very happy, proud and even more excited it."
