'Worst ever seen': Outrage over UFC fighter's 'horrible' act

Rodrigo ‘Kazula’ Vargas has been slammed by fight fans after his disqualification from UFC Fight Night in Rio Rancho, New Mexico.

The Mexican fighter destroyed any hopes of defeating Brok Weaver in their lightweight bout after producing a "disgusting" act of foul play.

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Vargas was on top in the fight against Weaver, who was pinned on the ground next to the octagon cage in the opening round.

Despite knowing that kneeing an opponent in the head while they're down is illegal in UFC, Vargas struck the American with a brutal blow regardless.

He then inexplicably followed up the illegal knee with a series of follow-up punches before the referee stepped in to bring an end to the contest.

The controversial incident drew widespread outrage from viewers on social media.

‘As illegal a knee as I’ve seen’

Former heavyweight champion Daniel Cormier said in commentary that Vargas' actions were "as illegal as it gets".

“That’s as illegal a knee as I’ve seen in a long time," Cormier said.

“I don’t understand what Kazula Vargas was thinking there, throwing that knee.

“It landed illegally, he got knocked out.

Brok Weaver was handed the win after Rodrigo Vargas was disqualified for an illegal knee. Pic: ESPN/Getty

“It’s the right decision. He’s flat on his butt, he’s not even up on his knee where you could get confused.

“It’s the right call.”

The disqualification to Vargas handed Weaver his first win in the UFC, however, the American looked sheepish after his hand was raised in the post-fight ceremony.

“A win like that, it ain’t no win in my book,” Weaver said in a post-fight interview.

“In my book, he TKOd me. So, I lost tonight. I just got paid good.”