LAS VEGAS – Shocking the world is nothing new to former UFC bantamweight champion Holly Holm.

Holm turned the MMA world, if not the entire sports world, upside down when she knocked out Ronda Rousey four years ago in Australia. The title-winning performance remains one of the biggest upsets in the promotion’s history.

Now, Holm (12-4 MMA, 5-4 UFC) is on the cusp of a fight with two-division champ Amanda Nunes, the most dominant female force in the sport at the moment. UFC 239 is a moment to make history, and yet people are asking Holm about the end of her career.

At 37, Holm said people want to know when she’s going to retire with the accomplishments she’s earned in boxing and MMA. But she’s not done trying to pull off the upset.

“I understand that other people might think this is a shock, but for me to come in here, we really believe we can do this,” she told fans after an open workout at the MGM Grand hotel for Saturday’s event at T-Mobile Arena. “So to win this fight isn’t going to be shocking to us. But I hope the people who believe I can’t do it, I hope it shocks you.”

In terms of the outcome the public is predicting, the balance of power will not be upset. Holm is again the underdog in advance of UFC 239, though not as significantly favored to lose as before her fight with Rousey.

It’s no wonder, as Nunes (17-4 MMA, 10-1 UFC) has stopped three of her past four opponents with a barrage of fists. In her most recent fight, she sent Cris Cyborg face first to the canvas to capture the featherweight belt and hand Cyborg her first loss in 13 years.

Holm said there’s nothing she doesn’t know about the challenge ahead of her. All she knows is that the skills she brings to the table are unique.

“I know power is one of her things,” Holm said. “It’s not just the fight with Cyborg. I think that’s the one that stands out the most. It’s the most recent, and Cyborg’s known for the same thing, so it was that big of a big deal.

“There’s a lot of times that people have given her harder times that aren’t standing and banging with her. … Here’s the biggest thing about all that: I’m not Cyborg, I’m not Shevchenko, I’m not Miesha Tate – I’m Holly Holm, and this is going to be a totally different fight.”

If Holm beats Nunes, she will have an argument for being considered the all-time greatest female fighter in UFC history. Rousey was at her peak when she met Holm, and so is Nunes. But Holm will leave that designation to others. Her legacy will be written in her performances.

Retirement is something you do when you’re done trying to be the best, and Holm is far from there.

“Everybody keeps asking me what the final day is going to be, when I’m going to retire,” she said. “But I’m here fighting for a title, so I can’t even think about that.”

For more from Holm’s interview, click the video above, and to see her open workout, click on the video below.

For more on UFC 239, check out the UFC schedule.