Saul 'Canelo' Alvarez claimed the WBC and WBA world middleweight titles by inflicting a first career defeat on Gennady Golovkin with a gripping points win in their Las Vegas rematch.

The Mexican claimed a frenetic final round on two of the three scorecards which was critical in preventing a repeat of the draw both men shared 364 days earlier at the same T-Mobile Arena venue.

It gave him a narrow a 114-114 115-113 115-113 majority decision to edge a contest in which both men were cut and where each showed why they are among the finest practitioners in the sport.

Golovkin, whose first defeat comes in his 40th bout, left the ring immediately without conducting an interview as his rival - fighting for the first time since serving a six-month drugs ban - celebrated.

"My corner told me I needed to win the final round and that's what I did. I'm very emotional," said Alvarez, who has previously held world titles at middleweight and light-middleweight.

Golovkin told reporters afterwards: "I'm not going to say who won tonight, because the victory belongs to Canelo according to the judges. I thought I fought better than he did. We would like to have a third fight, we will negotiate that, that's what we want."