LAS VEGAS -- The legend of Poatan continues to grow.

Alex Pereira (11-2 MMA, 8-1 UFC) scored a vicious second-round knockout of Jirí Prochazka (30-5-1 MMA, 4-2 UFC) with a devastating head kick and brutal follow-up strikes to retain his light heavyweight championship in the main event of UFC 303 at T-Mobile Arena.

The rematch between the two, who met last November with Pereira winning by second-round TKO, happened a lot sooner than expected as both were called to action on two weeks' notice after Conor McGregor was forced out of his main event showdown with Michael Chandler due to a broken toe.

Both fighters had competed at UFC 300 and pulled off impressive knockout victories in their respective fights, with Prochazka taking out Alexander Rakic and Pereira impressively dispatching Jamahal Hill in defense of his title. Both left with little damage, but a pair of broken toes was the only thing in the way of Pereira accepting the fight.

As it turns out, those broken toes would connect on the head of Prochazka in the rematch and put an end to the rivalry.

"I didn't know how I was going to win, but I knew I was going to leave this Octagon happy," Pereira said through an interpreter.

The fight was a strikers' paradise in the opening round, with Pereira landing leg kicks and Prochazka finding success with the left hook and using his awkward movement to create openings. But Prochazka played too close to the sun and ran into Pereira's trademark left hook, which sent him crashing to the canvas at the end of the round. Although he tried to show he was unharmed, Prochazka's legs said otherwise as he stumbled to his corner.

Pereira smelled the blood in the water and wasted little time finishing the job. He opened the second round by uncorking a violent head kick that sent the Czech Republic fighter to the canvas again. But this time there would be no bell to save him as Pereira's follow-up strikes finished the job just 13 seconds into the round.

What Pereira has been able to accomplish in two short years is nothing short of outstanding. He captured the UFC middleweight championship in just over a year after his promotional debut by knocking out Israel Adesanya and added the light heavyweight title a year after that when he stopped Prochazka.

With another successful defense under his belt, could Pereira chase an unprecedented championship in a third weight class at heavyweight?

"I think that's in my future," Pereira said. "I say it a lot. I'm here, I'm available and I think that's in my future."

A fight with current heavyweight champion Jon Jones might be the biggest fight that can be made in the UFC at the moment, and it's clear that Pereira wants to continue to do the unthinkable during his remarkable run. But with Jones slated to face Stipe Miocic later this year, a fight with Pereira might have to wait.

For now, the MMA world is in the palm of his hand.