Alvarez won the last round on two cards which proved key

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."

'We will do it again'

All three judges had Canelo (left) leading 4-2 after six rounds

Alvarez looked close to tears after a decision which will again prompt controversy as, for spells in the fight, Golovkin seemed to be edging the physical side of a tactical battle, with his jab proving key early on.

But with scoring already criticised in their first bout before Alvarez's two failed doping tests in February, it is perhaps not surprising that once again controversy will remain attached to this rivalry, with demand for a third meeting almost guaranteed.

Few could argue the hype surrounding their second meeting was not justified as the bout ebbed and flowed. Celebrities including actors Will Smith and Denzel Washington, and sports stars such as Mike Tyson and LeBron James, sat ringside as more than 21,000 inside the arena were taken in by a bout in which neither man looked like capitulating even when under solid attack.

After Golovkin's poised jab clearly won the opening three minutes, Alvarez's response in the second - including a solid right uppercut - pointed to the back-and-forth contest that was to come.

All four judges gave 'Canelo' four of the opening six rounds despite some of the more eye-catching work coming from Kazakhstan's Golovkin, who landed a notable left hook in the fourth.

Alvarez is once again a middleweight world champion and has also held world titles at light-middleweight

But Alvarez - who sustained a cut above his left eye which worsened as the bout developed - visibly began to close distance in order to nullify Golovkin's jab. At times their heads were almost touching, bringing hooks and uppercuts into focus, and Golovkin sustained his own cut from a head collision.

Alvarez, a man steeped in the art of fighting with six brothers who also hold professional boxing records, remained game in walking forward repeatedly, a contrast to his a largely back-foot performance last time.

His mother was pictured praying at ringside after a ninth round which saw both men launch repeated attacks and Alvarez almost came unstuck in the 10th as a left hook to his jaw briefly rendered him limp, only for him to somehow quickly rediscover his poise.

But his work up close perhaps won the judges over. Ringside stats showed Alvarez landed 46 body punches compared to six from his rival but after landing a right to the body and left to the face in the final round, he ate two uppercuts in the closing 10 seconds as both men responded to the noise around them.

They embraced before each raising their hands but the cards prompted Mexican celebration on the country's Independence weekend.

"If the people want another fight then we'll do it again," said Alvarez, beaten only by Floyd Mayweather in a 53-fight career. "We'll do it, no doubt."

'Boxing needed this'

Alvarez looked to the sky as he was declared the winner

Former super-lightweight world champion Amir Khan: "What a fight. I gave the fight to Canelo. It was toe-to-toe action. Very exciting. Canelo surprised us all with the come forward pressure game plan. Well done to both Canelo and GGG. Boxing needed this."

LA Lakers basketball player LeBron James: "One of the best fights I've ever seen! Ultimate competitors in Canelo and Triple-G! Salute to the both of you. Could watch y'all fight any day."

Former world heavyweight champion George Foreman: "Canelo Brave as a Bull! Congrats! Made a puncher Box. I didn't expect this. Need one more between these great fighters."

Northern Irish featherweight Michael Conlan: "I don't think it was robbery, had Canelo winning and I really wanted Triple-G to win. Some very close rounds that could have gone either way. Canelo's body work, sharp counters and punch output stole it for me. Great fight with two great champions!"

Sydney 2000 Olympic gold medallist Audley Harrison: "I just can't see that result - Canelo did a great job but he didn't do enough to win in my opinion. Great fight, but GGG can feel that decision should have gone his way. No third fight for at least a year guys (long rest)."

Northern Irish featherweight Carl Frampton: "In hindsight a lot of the rounds were close. I edged to Triple-G but can we please applaud the smaller man Canelo's chin."

'A third fight in May?'

Golovkin's jab helped him win the opening round on all three cards

BBC Sport boxing correspondent Mike Costello in Las Vegas:

In essence the judges were only one round adrift and that's how close it was.

Controversy will be generated. There are bound to be boxing fans out there who felt Canelo won and there will be loads of people shaking their heads.

All judges were in agreement for the first six rounds, it was 4-2 at that stage and we ringside had it the other way around to Golovkin.

There will be an awful lot of talk for the next few weeks and that is one upside for the sport. It wouldn't have got this amount of talk had it not been a controversial result. If the third fight does happen, you would imagine it would happen back here in May next year.