A debatable and controversial decision to say the least, a third fight could be in the offing next year, which would certainly be an epic conclusion of the rivalry between two of the greatest exponents of the sport in the modern era.
Alvarez inflicted the first defeat of Kazakh slugger Golovkin's career after two judges scored it 115-113 in his favor, with another judge scoring it even at 114-114. Scores of 115-113 either way or a draw were easy conclusions to reach, meaning any talk of controversy is unwarranted.
Atlas added that he felt Golovkin was controlling the fight and deserved to win.
Unfortunately tonight's rematch didn't deliver a decisive victor, but it did give fight fans one of the greatest boxing matches in the history of the sport. Originally, the pair fought previous year in September in Las Vegas.
This carried on much the same in rounds eleven and twelve, with Canelo showing a granite chin to stand up to a hailstorm of Golovkin power shots. He had always claimed to have been the true victor of the first fight and had now missed out on career wins 39 and 40 due to contentious scorecards. A GGG victory, like I had it, or 2. The rematch had originally been scheduled for May 5 but a failed drug test, which Canelo blamed on tainted meat he had consumed, delayed it four months.
Golovkin came into the fight undefeated at 38-0-1, while Alvarez had lost only once, to Floyd Mayweather.
"Canelo did what he said he was going to do", Golovkin promoter Tom Loeffler said.
In what was a tightly contested bout throughout the night, many observers were split as to who would be leading this one, but the large consensus was that GGG outboxed Canelo, who was on the verge of getting knocked out at certain stages. But Alvarez removed the most negative stereotypes against him - save for his uncanny ability to receive the benefit of the doubt in a close fight - and heaped nothing but the praise of his opponents in doing so. Such was the manner of his win, though, a third and final fight between the pair is all but assured.