LAS VEGAS -- Amanda Nunes is the greatest female fighter in women's MMA history. End of conversation.

In case there was any doubt of that fact entering UFC 239 on Saturday, Nunes placed an emphatic exclamation point on her legacy by demolishing the last remaining former champion she had yet to face.

Nunes (18-4) sent the T-Mobile Arena crowd to their feet with a violent head kick that finished former bantamweight champion Holly Holm late in Round 1 as Nunes, the first female two-division champion in UFC history, defended her 135-pound crown with ease.

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"[This is] amazing," Nunes said. "A lot of people say whatever happens in Vegas, stays in Vegas. But this belt will always stay with me."

The 37-year-old Holm, who upset then-unbeaten Ronda Rousey with a similar head kick in 2015, fell to just 2-5 since that 2015 upset that made her an instant star. Holm (12-5), the former three-division boxing champion was never a factor against Nunes as the champion wore her down with hard right hands.

Nunes, 31, appeared to rock Holm with another clean right hand before landing a perfect right kick to the head that dropped her. The native of Brazil dove in to land a trio of punches as referee Marc Goddard stopped the fight at 4:10, even though Holm was attempting to stand (and eventually fell into Goddard's arms).

"I knew I would get her," Nunes said. "I told my coach I wanted to knock her out that way [with a head kick, Holm's specialty] and I did that. [Now] I definitely want to defend my 145-pound belt."

Despite her holding titles in two divisions, UFC may have trouble finding Nunes credible opponents after building an incomparable resume that saw her defeat former champions Rousey, Miesha Tate, Germaine de Randamie, Valentina Shevchenko (twice), Cris "Cyborg" Justino and Holm. The win also ties her with fellow Brazilian champion Jessica Andrade for the most wins by a woman in UFC history with 11.

UFC president Dana White reiterated after the fight that Nunes is the greatest of all time in his book. He also pointed out that he hopes Holm considers retirement after suffering a vicious knockout this late in her career.

For complete results from UFC 239, click here