The 24-year-old Filipino-Australian won the Philippines' fourth Miss Universe crown, pulling all the stops from a giant lantern strapped to her back, a slow-motion twirl in a hot pink bikini, and a long gown in flame hues that symbolized a mythical Filipino bird.
Fans screamed at the IMPACT Arena here as outgoing Miss Universe Demi Leigh Nel Peters from South Africa crowned her successor.
Pia Wurtzbach last won the Miss Universe crown for the Philippines in 2015 and the succeeding edition was hosted in Manila.
Tamaryn Green of South Africa was first runner-up followed by Miss Venezuela.
During the final question, Gray was asked "What is the most important lesson you've learned in your life and how would you apply it to your time as Miss Universe?"
She replied: "I work a lot in the slums of Tondo, Manila and the life there is... it's poor and very sad. And I've always taught myself to look for the beauty of it, to look for beauty in the faces of the children and to be grateful. And I would bring this aspect as a Miss Universe, to see situations with a silver lining, and to assess where I could give something, where I could provide something as a spokesperson. If I could teach also people to be grateful, we could have an amazing world where negativity could not grow and foster, and children would have a smile on their faces. Thank you."