Frankie Edgar is shopworn. He has been in too many wars, and he's too old. Moving down to bantamweight 15 years into his career? A last-gasp move.

Those were some of the storylines coming into the UFC Fight Night main event Saturday night in Las Vegas. Like he has so many times before, Edgar silenced the doubters.

Edgar defeated Pedro Munhoz by split decision (48-47, 46-49, 48-47) in his bantamweight (135 pounds) debut. Edgar, 38, is the former UFC lightweight (155 pounds) champion and was a perennial featherweight (145) contender. Now he has knocked off a top-flight bantamweight.

Edgar, who became the 11th fighter in modern UFC history to win in three divisions, addressed his critics in his postfight interview.

"I proved all them wrong," said Edgar, who cashed as a +235 underdog, according to the Caesars Sportsbook. "I still got some fight in this tank, and we're gonna make a run at [135]."

The card took place in front of no fans at the UFC Apex, a facility owned by the promotion across the street from its corporate campus. Coming in, ESPN had Munhoz ranked No. 7 among MMA bantamweights. Edgar is a surefire future UFC Hall of Famer.

"I'm showing I can compete with the best at 38 years old," Edgar said. "I don't want to hear nothing from nobody."

UFC president Dana White said he was impressed with Edgar's performance.

"The career that the guy has had has been unbelievable," White said. "The fact that he's still performing the way he's performing at his age with all the wars that he's been through, and all the things he's accomplished, yeah, I'd say he looked pretty damn good tonight."

Edgar vs. Munhoz was awarded Fight of the Night by the UFC, earning both men bonuses of $50,000. The two combined for the most significant strikes landed in UFC bantamweight history (301), with Munhoz landing 166 and Edgar landing 135.

The bout was extremely close and could have gone either way. Edgar showed from the outset that he was just as fast, sharp and quick at bantamweight as he was two weight classes above. But Munhoz carries big power and landed hard right hands in the first round.

In the second, Edgar started to take over with his technical boxing, landing combination after combination. A right hand opened up a cut to the side of Munhoz's left eye. Munhoz made an adjustment in the third round, going back to kicking Edgar's calf. It proved extremely valuable. Edgar, known for his footwork, was clearly diminished by Munhoz's chopping kicks.

The fourth and fifth rounds were tight. Both men had their moments -- Munhoz with the kicks and his big right hand, Edgar with his combinations. In the fifth, Edgar wobbled Munhoz briefly with a right hand. By the end, both men were bleeding from several cuts on their faces.

"I just got my feet wet," Edgar said. "I think the sky is the limit. I didn't look slow at all in there. ... Pedro is a top dog. That makes me a top dog."

White said afterward that Edgar was transported to the hospital after the main event due to the damage he took to his left leg from the Munhoz leg kicks.

"I'm sure his leg is really busted up," White said.

Judges Derek Cleary and Eric Colon scored the bout for Edgar. Judge Sal D'Amato had it for Munhoz. Cleary gave Edgar the second, third and fifth rounds, while Colon gave him the first, second and fifth. D'Amato had Munhoz winning all but the second round.

Edgar (24-8-1) had dropped two straight coming in, including a featherweight title defeat against then-champion Max Holloway. The New Jersey native had long thought about dropping down to bantamweight -- he was always the smaller man in fights at lightweight and featherweight -- and finally made the decision to do so last summer. Edgar was the UFC lightweight champion in 2011 and 2012. He was a perennial contender at featherweight after that, including competing in three title fights, all losing efforts.

Munhoz (18-5, 1 NC) has lost two straight. He was on a three-fight winning streak before falling to top contender Aljamain Sterling at UFC 238 in June 2019, his previous bout. The Brazil native, who lives and trains in Florida, owns a vicious knockout win over former bantamweight champ Cody Garbrandt. Munhoz, 33, has won seven of his past 10 fights in total.