LAS VEGAS — Alex Pereira first became a champion kickboxer and then moved to the UFC and won title belts in the middleweight and light heavyweight divisions.

And, after Saturday night’s convincing victory over top-ranked challenger Jiri Prochazka in UFC 303, he might not be done.

Pereira could move up to heavyweight and do what no UFC fighter has ever accomplished — win championships in three weight classes.

He put himself in position after delivering a vicious left kick to Prochazka’s head and then pounded him, ending the fight 13 seconds into the second round to retain his light heavyweight championship.

“I think that’s in my future,” Pereira, who is from Brazil, said through an interpreter. “I said that the last time I was here. I’m here, I’m available and I think that’s in my best interest.”

UFC President Dana White wasn’t ready to commit, noting his respect for heavyweight champion Jon Jones.

“We’ll see how this whole thing plays out,” White said.

Pereira (11-2) now has beaten Prochazka (30-5-1) twice since November to end any doubts about who reigns in that weight class.

Most of the drama at UFC 303 occurred outside the octagon in the weekend and even the hours leading up to the event.

“Hell of a month,” White said. “It’s been challenging, but fun.”

Officials had to act quickly after a late change was needed in the co-main event when an illness forced Brian Ortega to drop out.

Dan Ige already was in Las Vegas training for another fight and wound up taking on Diego Lopes in the lightweight fight.

All three judges scored the fight 29-28 in favor Lopes (25-6) of Brazil.

Ige (18-8), who is from Honolulu but lives in Las Vegas, was cheered loudly for showing up with little notice.

The UFC also scrambled to pair Pereira and Prochazka after scheduled headliner Conor McGregor’s broken toe forced him to withdraw.

They were given about two weeks to prepare after Pereira had his Australia vacation disrupted and Prochazka was interrupted while at a three-day meditation retreat.

A packed crowd of 18,881 that included New York Jets quarterback Aaron Rodgers, sitting next to former Green Bay Packers teammate Marcedes Lewis, watched.

Lewis now plays tight end for the Chicago Bears.

At $15.9 million, it was the fourth-highest gate in UFC history. White had hoped to break the record, but not having the star power of McGregor likely kept that from happening.

The highest gate is $17.7 million for UFC 205 in November 2016 at New York’s Madison Square Garden.

Pereira and Prochazka engaged in a lengthy staredown that carried through Bruce Buffer’s fighter introductions and referee Herb Dean’s instructions.

Both fighters spent the opening round feeling each other out, but there was a strong hint of what was to come as it ended.

Pereira knocked down Prochazka with a left hand, but it occurred after the bell.

Then Pereira finished the job.

“I’ve been saying all week that I was going to come out and be victorious,” said Pereira, who turns 37 on July 7. “I didn’t know how I was going to win.”

Prochazka, a 31-year-old from Czechia, was not made available to the media.

If Pereira does move up to heavyweight, that could help Prochazka in his effort to reclaim the belt he held briefly two years ago.

Second-ranked challenger Magomed Ankalaev and No. 3 Jamahal Hill also could have a big say in who rules the division.

Hill originally was scheduled to fight in the co-main event, but a knee injury while training forced him out.

Prochazka’s bout with Pereira was a rematch from Nov. 11 at Madison Square Garden.

Pereira won the championship that night with a technical knockout at 4:08 of the second round to claim the vacated light heavyweight champion.

Then Pereira cemented his hold on the belt by beating previous title holder Hill with a first-round stoppage in UFC 300 on April 13 in Las Vegas.

On the same card, Prochazka recorded a second-round TKO of Aleksandar Rakic to put himself in position for the earlier-than-expected rematch.

Mayra Bueno Silva (10-4-1) suffered a gash so big in her bantamweight fight that the ring doctor called the fight at 1:58 of the second round in favor of Macy Chiasson (11-3). Blood poured down Silva’s face, who asked to continue.