Dricus Du Plessis successfully defended the UFC middleweight championship by defeating Israel Adesanya with a fourth-round submission Saturday in the main event of UFC 305 from the RAC Arena in Perth, Australia.

Du Plessis (22-2 MMA, 8-0 UFC) had to overcome adversity to retain his belt, as Adesanya (24-4 MMA, 13-4 UFC) was building a head of steam in the fourth round before a left hook stunned the former champion and led to the finishing sequence.

It was a nip-and-tuck affair through three rounds, between Du Plessis' explosive offense and takedowns and Adesanya's pinpoint counterpunching and bodywork. Just as it appeared the bodywork was slowing down the champion in the fourth round, Du Plessis dug deep and charged forward, slamming a trio of right hands into Adesanya and securing a takedown. Du Plessis quickly transitioned to the former champion's back and sank in a rear-naked choke to get the submission at the 3:38 mark.

"I came in here to die for this belt or take a life," Du Plessis said. "Luckily, I didn't have to do either."

The fight had more on the line than a world title as Adesanya and Du Plessis had been engaged in a war of words for over a year regarding who the first "real" African champion was. Adesanya was born in Lagos, Nigeria, but currently resides in Auckland, New Zealand, while Du Plessis was born and raised in Pretoria, South Africa.

The rivalry became a battle of heritage once Du Plessis disregarded previous African-born UFC champions Adesanya, Kamaru Usman and Francis Ngannou, stating that he was the first champion born, raised and currently residing on the continent.

Although there was bad blood heading into the fight, the two fighters seemed to bury the hatchet afterward.

"I'm really sorry that it came across that I disrespected the fact that he's from Africa," Du Plessis, 30, said afterward. "That was never my intention. Africa would have won regardless, but tonight South Africa was the victor.

"It was an honor for me to share this cage with a legend, and I have the utmost respect for him."

It was Du Plessis' 10th straight win and first successful title defense after beating Sean Strickland for the championship in January. His first defense would be against the man who many believe is one of the greatest middleweights of all time.

Adesanya, 35, was returning to the Octagon after an 11-month layoff following his stunning title loss to Strickland last September. The former champion took a sabbatical from fighting after competing at a breakneck pace of six title fights in 19 months and hoped the time off would produce an improved version of "The Last Stylebender."

The former champion did look good throughout the fight, using his pinpoint counterstriking, long jab and body punching to score. Adesanya actually had a 105-99 edge in total strikes, according to UFC Stats.

But Du Plessis remained explosive and mixed striking with takedowns to keep his opponent honest. After Adesanya stuffed Du Plessis' takedown attempt in the first round, "Stillknocks" would be persistent and secure three takedowns in the second round while also threatening a rear-naked choke. It would be that transition from takedown to choke that would end up being the successful combination to retain the title.

In Rounds 3 and 4, Adesanya began to slide into a rhythm, firing jabs and ripping body shots that affected the champion. But, as always, Du Plessis found a way to power through when the going got tough and picked up his biggest win to date.

As for Adesanya, who suffered the first submission loss of his MMA career, there were questions surrounding his future if he fell short in his attempt to retain the title, but he had a message following the loss.

"I'm not f---ing leaving," he said.

UFC president Dana White announced before the fight that Strickland would be next in line for the winner. It would be a return bout for Du Plessis, but he said he has no qualms with giving Strickland another crack at the title.

"I want to hear 'And still,'" he said. "That's the only thing I care about. I don't care about the opponent."