The fighter dispatched Tate -- who has held the title since March after defeating Holly Holm -- in just over three minutes. She credited her development to training partner and girlfriend Nina Ansaroff, who fights in the UFC women’s strawweight division.
"Nina is the best training partner I've ever had in my life," Nunes said. "This girl is going to be the next UFC champion. I'm telling you... This girl has so many talents.
"She means everything to me,” she added. “This girl, she helps me with everything... I love her."
Nunes’ title victory comes less than a month after the massacre at Pulse nightclub in Orlando, Florida, where 49 were killed after a gunman opened fire at the gay nightclub.
"It's very sad," Nunes said of the shooting. "I wish these things didn't happen anymore. Peace in the world is very important. I don't think the U.S.A. is gonna let this happen anymore. It's gonna stop."
The UFC is also stepping up its support of the LGBTQ community with its new "We Are All Fighters" campaign. Light heavyweight champion Daniel Cormier and Mark Hunt wore the shirts this week ahead of UFC 200.
"Just as it takes courage to step into the Octagon, it takes courage to stand for what you believe in -- and we're proud to stand with members of the LGBTQ community in their fight for equality," UFC senior executive vice president and COO Lawrence Epstein said in a statement. "As friends and allies of the LGBTQ community, our hope is to raise awareness and help support community groups like the LGBTQ Center that directly impact LGBTQ individuals."