Alvarez took Golovkin’s titles with a 114-114 115-113 115-113 majority points decision after the fight went the full 12 rounds.
Golovkin had previously gone 39 bouts without tasting defeat, but his incredible record came to an end after Alvarez failed to read the script.
There was little separating the two titans during the first few rounds of an absorbing contest.
But after Golovkin worked the jab well, Alvarez came into his element and by the 10th round, the Mexican produced a lovely right hook.
Golovkin was finding a lot of joy with his jab and even cut Alvarez’s eye.
Both fighters laid their souls on the line in the last couple of rounds.
Despite Golovkin’s cheekbones looking very swollen and blood pouring out of Alvarez’s face, the contest went to the judges’ scorecards.
One had it as level, while two scored it 115-113 in Canelo’s favour.
Speaking ringside after his victory, Alvarez said: “My corner told me that I needed to win the round [final round] and that what’s I did.
“I’m very emotional. That’s what I did. I promised the people I would go for a knockout. He’s a very good fighter.
“I did this for Mexico.
“Again he was connecting punches but they were few and far between.
“He’s a great opponent but every fighter depends on the fighter. Every great fighter has a great rival.”
On asked whether he would like a rematch, Alvarez added: “If the people want another fight then we’ll do it again. We’ll do it, no doubt.”
Golovkin, however, refused to do his customary interview and headed straight back to his changing room amid a chorus of boos from the crowd.
Alvarez could now defend his titles against David Lemieux, who knocked out Gary ‘Spike’ O’Sullivan on the undercard.
A third instalment of this trilogy however appears to be something the fans would crave.