Saul 'Canelo' Alvarez reigned supreme over the super-middleweight division on Saturday evening after ending his trilogy against Gennady Golovkin with a thrilling unanimous decision victory.
The Mexican arrived into the fight hoping to end the rivalry between the pair following their two bouts in 2017 and 2018 respectively.
Las Vegas was the venue once more and Canelo had control of the fight for most of its duration against an unusually subdued Golovin.
The Kazakh fighter tried to rally in the latter stages but Canelo was able to successfully sidestep any counter-attacks and he retained his IBF, WBA (Super), WBO, and WBC titles.
The fight had been long anticipated - four years on from their previous bout when Canelo won with a majority decision.
The Mexican came out of the blocks quickest against his 40-year-old opponent and looked strong particularly with his left hook, despite showing no real signs of seriously hurting Golovkin.
The rounds were passing by and Golovkin could not muster any rhythm against Canelo, who was returning to the super-middleweight division following his unsuccessful exploits at light-heavyweight level.
Later in the fight, Golovkin began to fire back with his jab causing Canelo to backpedal but the 32-year-old was able to power through despite showing visible signs of fatigue.
Ultimately, Golovkin could not achieve what would have been a 38th career knockout and, once the bell was sounded for the end of the 12th round, he must have been fearing the worst owing to his very slow start to proceedings.
Despite the bitter build-up heading to the United States, the two fighters showed great respect for one another upon the conclusion of the bout.
Interviewed afterwards, Canelo was very complimentary towards his opponent and long-time rival, saying: "Thank you my friend, we gave the fans three great fights."
Golovkin said: "I want to shake hands with Canelo. Congrats to all his team. He's a real warrior - if you don't understand that, you don't understand nothing."
Since Canelo last fought Golovkin, he has continued to be a winning machine at middleweight and super-middleweight levels.
Rocky Fielding, Daniel Jacobs, Sergey Kovalev, Callum Smith, Avni Yildirim, Billy Joe Saunders and Caleb Plant have all challenged and failed to beat the Mexican, who is widely regarded as one of the best pound-for-pound fighters of his generation.
He had amassed many belts and championship titles in those weight categories and made the decision to step up to light-heavyweight level once more following the win against Kovalev for the WBO title.
Canelo Alvarez vs Gennady Golovkin III - Boxing: All you need to know
Jake Paul vs Anderson Silva - Boxing: All you need to know
Standing at just 5ft 8, Canelo signed a deal to fight Russian Dmitry Bivol and was the heavy favourite to win despite his relative lack of experience.
However, Bivol was very lively in the fight and won by virtue of a unanimous decision - Canelo struggling against the punching power of his opponent, who outlanded him in every round of the fight.
Judges declared Bivol the winner and Canelo made the decision to step back down to super-middleweight level.
However, he wants to avenge what was just the second defeat of his professional career following a majority decision loss to Floyd Mayweather in September 2013.
Canelo does concede though that he needs to rest and potentially requires surgery on his hand following his 62nd career fight.
"I left everything in there. I need surgery on my hand, I'm not good in my left hand," he said. "Everybody knows [Bivol is the fight I want]. We'll see what happens in that fight. But I need rest.
"It's very important for my legacy, for my pride, for my family and my country. I will beat him."
Bivol's next fight is on 5th November against Gilberto Ramirez and he is 1/6 to win with Ramirez 7/2.
Golovkin has won every fight he has taken part in that has not been against Canelo but, sadly, he may end up being defined as the man who could not get the better of him in three fights.
Arguably in the first fight that ended in a draw, he was the better man on the night and the split decision was certainly a controversial one.
The result on Saturday surely ends any hope of him reigning supreme over the super-middleweight division but Golovkin has promised to not give up just yet, despite now being in his 40s.
"I still have this fire burning within me. I have the passion for boxing. Don't forget I have three belts at 160lbs. I feel great," he said confidently.
Golovkin still retains IBF, IBO and WBA (Super) belts at middleweight level and will probably drop down once again if he is to continue.
Latest sports betting and odds
Head to the bet365 YouTube channel for exclusive boxing content