Amanda Nunes is the greatest women's MMA fighter of all time. She holds the UFC titles at bantamweight and featherweight. On top of that, she has beaten every other woman who has held either one of those belts. But, according to Nunes herself, even the GOAT can have weaknesses. Whether or not her foe can exploit them? That might be a different story.

"I'm a human," Nunes told reporters Wednesday. "Everyone has holes in the game. But it's harder when you're in front of that person to really see that. This is, I feel like, the biggest thing with my opponents. They think they'll be able to see all my holes. But when they step in front of me, they know everything is different."

Nunes will defend her featherweight belt against Felicia Spencer at UFC 250 on Saturday night at the UFC Apex in Las Vegas. Nunes is trying to become the first fighter in UFC history to defend two titles simultaneously. She has held the bantamweight title since 2016 and the featherweight belt since 2018.

Nunes (19-4) has won 10 fights in a row going back to 2014, with five bantamweight title defenses in that span. The Brazil native has the most wins in UFC history among women (12) and the most wins in UFC title fights among women (7). Nunes, 32, has wins over the likes of Ronda Rousey, Cris Cyborg, Holly Holm, Miesha Tate and Valentina Shevchenko.

Spencer (8-1) stopped Zarah Fairn Dos Santos via first-round TKO in February to earn the title shot. The Florida resident is trying to become only the third Canadian to ever win a UFC title. Spencer, 29, has only one career loss -- to Cyborg at UFC 240 last July.

In the co-main event, former bantamweight champion Cody Garbrandt will try to snap a three-fight winning streak against Raphael Assuncao. Another huge bantamweight title fight -- UFC president Dana White has called it a No. 1-contender bout -- will pit Cory Sandhagen and Aljamain Sterling.

Also on the UFC 250 card, blue chip bantamweight prospect Sean O'Malley faces veteran Eddie Wineland, Neil Magny takes on Anthony Rocco Martin at welterweight and top flyweights Jussier Formiga and Alex Perez square off.

Brett Okamoto, Marc Raimondi and Jeff Wagenheim recap all the action as it happens on Saturday night.

Fight in progress:

Men's bantamweight: Cody Stamann (18-2-1, 4-1-1 UFC, -260) vs. Brian Kelleher (21-10, 5-3 UFC, +220)

Results:

Middleweight: Maki Pitolo (13-5, 1-1 UFC) defeats Charles Byrd (10-7, 1-3 UFC) via second-round TKO

Recap to come.

Men's flyweight: Alex Perez (24-5, 5-1 UFC) defeats Jussier Formiga (23-8, 8-5 UFC) via first-round TKO

Perez is someone to keep an eye on in the flyweight division. In the best performance of his career, Perez stopped Formiga via TKO (leg kicks) at 4:06 of the first round.

Calf kick is literally a game changer in this sport

— James Vick (@JamesVickMMA) June 6, 2020

Perez looked excellent standing up throughout the first round and his volume of hard calf kicks put Formiga down twice before referee Keith Peterson stepped in to call it off.

Perez landed 15 leg kicks in total, per UFC Stats. Perez becomes only the 11th fighter to win a UFC fight via TKO due to leg kicks.

Coming in, Formiga was ESPN's No. 6 flyweight, while Perez was No. 10.

Afterward, Perez said he's gunning for the title shot next. The flyweight title is currently vacant, but Deiveson Figueiredo and Joseph Benavidez are supposed to rematch for the belt this summer.

"I want that title shot -- 2020 is my year," Perez said.

Perez, 28, has won three in a row and 11 of his last 12. The California native has just one loss in seven UFC fights, to Benavidez in 2018.

Formiga, a 35-year-old Brazil native, has lost three straight.

-- Raimondi

Watch this fight on ESPN+.

Light heavyweight: Devin Clark (11-4, 5-4 UFC) defeats Alonzo Menifield (9-0, 2-0 UFC) by unanimous decision

Menifield came in as essentially a one-round fighter, undefeated with a finish in every win, all but two in Round 1. Clark had gone a full three rounds in five of his previous UFC bouts. That turned out to be the difference.

Clark absorbed an early punch to the left eye that left him wincing for much of the first round and provided a target for the aggressive Menifield. But Clark never faded and took over the fight as Menifield's energy sagged.

Man I'm always rooting for @brownbearC

Say what you want about his skills or fight approach, this man is next level Midwest tough. He's constantly got the next big thing and boogie man up and comers across from him.

— Anthony Smith (@lionheartasmith) June 6, 2020

Clark was rewarded by the judges, who handed Menifield his first career loss (30-27, 29-28 and 29-28).

Clark was busier the whole way and kept Menifield in a clinch against the cage for extended periods. Menifield had no room to wing his big punches -- when he still had the energy to do so.

Clark attempted takedown after takedown, and while his first eight failed to materialize, defending them sapped Menifield further. Finally, in Round 3, Clark got the fight to the ground. Thus he became the seventh 205-pounder with 20 takedowns in his first six UFC fights.

-- Wagenheim

Wach this fight on ESPN +.

Catchweight (150 pounds) Herbert Burns (11-2, 2-0 UFC) defeats Evan Dunham (18-9-1, 11-9-1 UFC) via first-round rear-naked choke

The Burns family has enjoyed a heck of a two-week span in Las Vegas. Lightweight Herbert Burns, the younger brother of welterweight contender Gilbert Burns, recorded a rear-naked choke just 1:20 into the opening round.

Herbert's victory came exactly one week after Gilbert solidified himself as a top contender at 170 pounds in a dominant decision win over former champion Tyron Woodley.

These Burns brothers are a PROBLEM ?@HerbertBurnsMMA got the quick tap at #UFC250 pic.twitter.com/hS8PQ80ph0

— ESPN MMA (@espnmma) June 6, 2020

Burns, 32, took Dunham to the floor early and controlled him from the back with a body triangle. Dunham is known for his strong grappling, but Burns is a former world champion in Brazilian Jiu-Jitsu and proved to be far too much for the American.

It is Burns' fifth finish in a row, and fourth inside the first round. Burns improves to 2-0 in the UFC. He also picked up a victory on Dana White Contender Series, in a fight that actually also took place at the Apex.

-- Okamoto

Watch this fight on ESPN+.

Still to come:

Women's featherweight: Amanda Nunes (c) (19-4, 13-1 UFC, -650) vs. Felicia Spencer (8-1, 2-1 UFC, +475)

Men's bantamweight: Raphael Assuncao (27-7, 11-4 UFC, -115) vs. Cody Garbrandt (11-3, 6-3 UFC, -105)

Men's bantamweight: Aljamain Sterling (18-3, 10-3 UFC, -115) vs. Cory Sandhagen (12-1, 5-0 UFC, -105)

Welterweight: Neil Magny (22-8, 15-6 UFC, -135) vs. Anthony Rocco Martin (17-5, 9-5 UFC, +115)

Men's bantamweight: Eddie Wineland (24-13, 6-7 UFC, +400) vs. Sean O'Malley (11-0, 3-0 UFC, -500)

Men's featherweight: Alex Caceres (15-12, 11-10 UFC, +160) vs. Chase Hooper (9-0-1, 1-0 UFC, -180)

Middleweight: Ian Heinisch (13-3, 2-2 UFC) vs. Gerald Meerschaert (30-12, 6-4 UFC)