'Best party crasher ever': How Maria Oliveira's Vegas caper led to friendship with pop star Anitta

Anitta's chart-topping exploits include the hit song "Envolver," which has amassed nearly 250 million views on YouTube. Emma McIntyre/Getty Images

Anitta, one of the hottest female pop stars in the world, posted a video on her Instagram story the morning of April 3. In the clip, Anitta was in a bed, still wearing the same outfit she wore the night before at her exclusive birthday party in Las Vegas.

Talking into her smartphone camera, Anitta appealed to her 62 million Instagram followers. There was a woman, she said, who crashed her party as an uninvited guest, and she wanted to find out who she was. There was no malice in Anitta's voice. The Brazilian recording artist liked the party crasher so much that she wanted to ask her to go out with her and her friends again later that night.

"I don't know who she is or how she crashed the party," Anitta said in the Instagram video, translated into English. "We realized she was a party crasher, but she was so fun and we loved her and we all danced until the party was over. We want to know who you are. ... Where are you girl? We loved you and we want you to go out with us tonight!"

Anitta posted another clip of her and the party crasher dancing together at the party. Within seconds of the Instagram stories going live, the party crasher's phone started to ding as people recognized her and started tagging her on Anitta's page.

The crasher? UFC women's strawweight Maria Oliveira.

Oliveira, from Rio de Janeiro, Brazil, resides in Las Vegas and trains at the UFC Performance Institute. Oliveira fights Saturday at UFC Austin against countrywoman Gloria de Paula. But the last two months of her life have been a whirlwind -- from crashing Anitta's party to becoming friends with the famous musician to gaining hundreds of thousands of Instagram followers almost overnight.

It has been a lot to take in for a 25-year-old Brazilian fighter who remembers dancing to Anitta's hit single, "Show das Poderosas," as a teenager with schoolmates back in 2013.

"Everyone wanted to dance like her," Oliveira told ESPN through an interpreter. "Everyone wanted to be her. I used to dance with my friends. I remember telling my friends, 'Imagine if Anitta sees us and how well we dance and how much we love her.' It's crazy to think I've been to her concerts and I've been with her and left with her and I was so close to her. So, this is pretty crazy to me, getting to know her."

Oliveira has been an enormous fan of Anitta since the beginning of the pop star's career. She used to send Anitta direct messages on Instagram telling her how much she loved her dancing and her music.

So, when Oliveira found out that Anitta would be having her birthday party on April 2 in Las Vegas -- where Oliveira has been living temporarily because of her MMA career -- she knew she had to see her. The location of the party was a secret, but Oliveira (with an assist from teammate and former UFC women's strawweight champion Jessica Andrade) scoured the Instagram pages of Anitta and Anitta's friends for clues as to where it would be.

Oliveira recognized some of the areas where Anitta's friends were posting from and narrowed down the location to the Park MGM resort and casino. Oliveira and a friend began to get dressed and ready with the expectation that they might be able to crash the party. They arrived at the Park MGM and walked around the property until they saw a club that looked like the one from the Instagram posts of Anitta's friends. As they got closer, Oliveira heard Brazilian funk music pumping from the speakers -- she knew she had found the one.

Then, there was the matter of getting in. Oliveira said she watched the three security guards working the door to see their process. One was checking the guest list, another was stamping hands and another was checking the stamps. Once she understood the workflow, Oliveira saw a group of men and slipped into line with them as if she was in their party. It worked. She got her hand stamped and entered the club before anyone realized she was not with those men. Oliveira's friend, unfortunately, was not able to sneak in. Oliveira would have to continue on her mission without her.

"I just wanted to dance and see Anitta," Oliveira said. "I didn't need to meet her. I just wanted to see her close. I know she doesn't like people who crash her parties and literally she kicks people out. She doesn't like it and this is something everybody knows."

It wasn't a big party, but once she entered, Anitta was visible immediately. Oliveira got a drink to blend in, though she didn't drink any of it in case she received a call from the UFC about an upcoming fight. And then she started dancing.

Anitta, Oliveira said, was in a group with other famous stars like the deejay Diplo, Venezuelan influencer Lele Pons and Brazilian actress Agatha Moreira. But, Oliveira said, "I could only see Anitta." The problem was, Oliveira needed to stay under the radar. She didn't want Anitta to see her, realize she wasn't invited to the party and then kick her out.

"I was dancing the whole time," Oliveira said. "Many times she came close to me and I would turn my head."

But Oliveira continued dancing. As one of Anitta's songs played, Oliveira started dancing near the floor like Anitta does in her music videos. When she looked up, she realized a woman was dancing with her.

"And who was on the top of me?" Oliveira said. "Anitta. She was literally behind me on the top of me dancing. ... I froze. Like, 'Oh my gosh, Anitta is right behind me. She's dancing with me. This is crazy.'"

Oliveira climbed up on top of a speaker and started dancing on it, but she said security told her to get off. Then, she got Anitta to join her on the speaker, and the two danced together. Anitta talked about that moment in her Instagram video, as well.

"Here's the lesson from this girl to all: if you want to be a party crasher go with a good vibe like that," Anitta said. "My friends are talking to me here and saying that they all thought she was my friend because she was fun and getting along with everyone. If you want to crash a party be like that. Don't go to spread gossip afterwards."

Oliveira didn't get to talk to Anitta that night, as they left the party separately. But the following day, after word got out that Oliveira was the crasher, Anitta sent her a voice message on Instagram through a friend. Anitta and her friends wanted Oliveira to go out with them that night -- and she did.

The two have kept in touch via Instagram, and Anitta invited Oliveira to the Billboard Music Awards with her in Las Vegas. Anitta performed at the show. Oliveira met her at the hotel, watched her get her hair and makeup done and then took in the performance at the MGM Grand Garden Arena. Oliveira said Anitta found it interesting she was a UFC fighter, telling all her friends that and asking "a lot of questions" about her MMA career. Anitta even offered Oliveira a job to join her and her team on the road.

"I thought about it, but I have my career," Oliveira said. "Of course, I still think about it. As long as it doesn't hurt my career, it would be very interesting."

The weekend of Anitta's birthday party, Oliveira gained 107,000 followers on Instagram. She has since gone out with people she met with Anitta, including famous Brazilian pop star MC Rebecca.

Oliveira said her followers have dropped in the last few weeks as she's gotten deeper into her training camp for UFC Austin. She joked that juggling her newfound influencer fame and budding fight career has been difficult. Oliveira is 12-5 as a professional MMA fighter and is trying to rebound from a loss to Tabatha Ricci last October in her UFC debut.

The one thing she doesn't have to worry about is sneaking into another gathering hosted by Anitta or her friends.

"Next year, she'll be invited to my party. She won't be a party crasher anymore," Anitta said on Instagram. "We found the party crasher. She explained how she crashed the party. She's amazing. She took care of my super drunk friends.

"Best party crasher ever."