It was just a few hours after her fight with Rin Nakai in Brisbane, Australia and Leslie Smith was walking around the Lone Pine Koala Sanctuary with her boyfriend Kevin Lum. Smith saw a notification on her phone from UFC matchmaker Sean Shelby, but thought it was a mistake.

About an hour later, Smith ran into Shelby at the zoo. He told her that the UFC was still looking for an opponent for Cris Cyborg at UFC 198 and the promotion was having trouble finding someone for her to face. Lum said Smith had sparred with Cyborg before. And Smith added that she'd absolutely be interested in fighting the Brazilian superstar.

The fight became a reality not too long after. And the UFC made it official by announcing it Monday: Cyborg will be making her UFC debut against Smith at UFC 198 on May 14 in Brazil. The bout will take place on the main card of a soccer stadium show in Cyborg's native Curitiba.

UFC president Dana White tweeted Monday that Smith was the only one who wanted to move up in weight and fight Cyborg, the pound-for-pound best women's fighter in the world and the Invicta 145-pound champion. Smith fights in the UFC's 135-pound division and the promotion doesn't even have a weight class at 145.

"I can't believe that other people didn't take it," Smith said. "I seriously can't believe that nobody else wanted this fight. As fighters, we're adrenaline junkies. We're just straight up adrenaline junkies. This is gonna be one of the biggest rushes that I possibly could have asked for."

Right after she spoke to Shelby in Australia, Smith made sure to message Cyborg on Facebook. Smith wanted Cyborg to hear the news from her first since the two have a solid relationship.

"She is my friend and she did invite me to spar in the past," Smith said. "I have a lot of respect and appreciation for her."

Cyborg, Smith said, had no problem with the matchup. Cyborg had been campaigning to fight at UFC 198 since it's in her hometown and would be her first UFC fight.

It's not surprising that other 135-pounders didn't want to face Cyborg. The fight will be at a catchweight of 140 pounds and in front of more than 40,000 fans in Cyborg's hometown. On top of that, Cyborg is probably the most dangerous woman to fight in the world. Few would want to derail their contender status at 135. Smith, though, wasn't thinking of it like that.

"Why did I want this fight so bad?" Smith said. "Because this is the biggest non-title fight and it might even be bigger than some of the title fights for a woman to take. And that's what I'm here for. I'm here to take the biggest fight that I can possibly get. I'm not just here to hang out and be like, 'I'm a UFC fighter. Yeah, I swear.' I'm trying to take the biggest fights that I could possibly take."

Smith (8-6-1) has won two of her last three fights and is coming off a unanimous decision win over Nakai. But she has no designs on a title fight. She said she would never fight bantamweight champion Miesha Tate, who made the call to Shelby to get Smith into the UFC.

"She's as much a teammate as anybody else to me," Smith said. "So I'm never gonna challenge her. I'm never going to fight her. So, this is the biggest fight that I can pursue."

Smith, 33, isn't one to back down from a challenge and she has a reputation for being one of the toughest women in MMA. She's competed in the past at 145, 135 and 125 pounds. She's fought Sarah Kaufman twice and top 125-pounder Barb Honchak. Smith had her ear nearly torn off against Jessica Eye at UFC 180 in 2014 and wanted to keep fighting. "The Peacemaker" also owns wins over Raquel Pennington and current Invicta interim flyweight champion Jennifer Maia. Smith has never been finished in a pro fight.

And now she'll be the first woman in the UFC to challenge Cyborg, the most frightening female knockout artist ever.

"I'm not scared to do it," Smith said. "I'm excited about doing it. Obviously, if I didn't have butterflies in my stomach, I'd be some kind of a psychopath, because I do still have a naturally functioning body that says, 'Hey, this is dangerous, get smart.'

"This is what I want. This is the adrenaline. This is gonna be a good fix."

Now that this is all a reality, Smith believes more than ever that she is the perfect woman for this job.

"The more we thought about it, the more I thought, I am the best possible person to fight her," Smith said. "Even if everybody else was knocking down [Shelby's] door, which they weren't, to get the fight, I've never been knocked out, I've never been tapped out. I've only ever lost by decision. It's been amazing fights any time that it's gone all the way. I'm a gamer. I've never come in fighting scared. I never have and I never will. That's where most of her past opponents have lost before they ever stepped in the cage. They came in just thinking defense and thinking about how long they can postpone losing. That is exactly what I'm not thinking about."

Smith wanted a big fight and this certainly qualifies. Plus, her contract with the UFC expired after the Nakai bout and this earned her an extension for more money. Smith said she made $10,000 to show and $10,000 to win against Nakai. Against Cyborg, she'll get $25,000 to show and $35,000 if she wins.

"I'm like the perfect person for this fight," Smith said. "We both like to stand and bang. It's going to be an exciting fight. It's gonna be a legendary fight. ... There's not a bigger fight than anybody can ask for than Cyborg. And I got it. I'm on Cloud 9 right now."

After the bout was signed, Smith said Shelby sent her a joking text.

"Remember," Smith said he wrote, "this fight was made between two dingos and some koalas."

And it'll be contested between two fearless women in front of a huge, raucous crowd.