LAS VEGAS (AFP) — Saul "Canelo" Alvarez has been warned that his legacy is in danger if Gennady Golovkin wins the third fight of their epic trilogy in Las Vegas on Saturday.

The Mexican superstar is putting his super-middleweight titles on the line against his bitter rival from Kazakhstan knowing a second loss in succession following his light-heavyweight defeat to Dmitry Bivol earlier this year would be a disaster.

Promoter Eddie Hearn reckons Alvarez can't afford a second defeat on the spin, but the 32 year-old looked in excellent shape during the weigh-in on Friday which was attended by hundreds of his fans in the sweltering Nevada heat.

Alvarez tipped the scales at 167.4 pounds (75.93 kg) with Golovkin slightly heavier at 167.8 lbs.

The Matchroom promoter said: "If Canelo loses I think he's in a terrible position coming off back to back defeats." He was pound for pound number one, all of a sudden, you probably put him outside of the top 10 if Golovkin wins.

"It will be such an epic fight and victory that everyone will want to see it again. (Golovkin)has already shared 24 rounds with Canelo. He knows how to fight him. It's not like he's got to go in and find out the best way to beat him on the night."

While Alvarez is the firm favorite with the bookmakers in Las Vegas, Golovkin, 40, should not be underestimated and has a serious chance of avenging the only defeat of career which was administered by Alvarez in the pair's second fight back in 2018 which ended in a very tight points decision for the Mexican.

"This is a trilogy fight between two of the modern greats, two warriors desperate to win," added Hearn, who believes Golovkin is far better suited to the super-middleweight class than trying to make 160lbs for the division below where he holds three belts.