Las Vegas - Canelo Alvarez bids to add another chapter to his legacy on Saturday when he steps up two divisions to face WBO light-heavyweight champion Sergey "Krusher" Kovalev in Las Vegas.
The 29-year-old Mexican middleweight king (52-1-2, 35 KOs) is regarded as the betting favourite for what is set to be a clash of youth and speed against Kovalev's experience and raw punching power.
Alvarez is fighting for the first time since a unanimous decision over Daniel Jacobs in May while Kovalev successfully defended his belt with an 11th round knockout of Britain's Anthony Yarde in Russia in August.
Although Alvarez has fought at multiple weight divisions, he has never before fought beyond the super-middleweight limit, where he battered Britain's Rocky Fielding into submission inside three rounds last year.
Kovalev (34-3-1, 29 KOs) is likely to prove a tougher nut to crack.
Even allowing for the fact that the 36-year-old has shown clear signs of ageing in some of his recent outings, the Russian remains a heavy-handed threat.
"He's the best in his division, he's one of the best, that's why we chose him, to make history by fighting one of the best," Alvarez said this week.
"I feel comfortable, I feel good, we'll see on Saturday how it all goes but I feel good. I trust my endurance, my strength."
Although Alvarez has already shown his ability to absorb punishment, most notably in his two bruising battles with Gennady Golovkin, Kovalev's power could cause him problems.
Kovalev meanwhile sees his fight with Alvarez as an opportunity to resurrect his career in the eyes of the boxing world.
The Russian lost his WBA, IBF and WBO belts in back-to-back defeats to Andre Ward in 2016 and 2017, but regained a share of the title after beating Colombia's Eleider Alvarez in a rematch in February.
"I'm happy," Kovalev said. "It's nice that this is the biggest call in my boxing career, and to face Canelo, I'm happy.
"This is a big test for me - to prove one more time, I'm the best light heavyweight in the division."
Kovalev said he expects Alvarez to adopt an aggressive tactical approach - and plans to meet fire with fire.
"This fight is going to be very interesting and very difficult for both of us because we never step back, never give up," he said.
"My goal is to break his strategy and use my strategy in the fight.
"We're two great champions, and right now we respect each other inside and outside the ring. We will be fighting, never step back, never give up, we'll make a great fight 100%."
If Kovalev manages to upset Alvarez, however, his joy may be short-lived.
On November 25 he is due to stand trial in San Bernardino Superior Court on charges of felony assault by means of force likely to cause great bodily injury.
The case dates back to an incident in the Californian mountain town of Big Bear last year, when Kovalev was arrested on charges of punching a woman in the face, leaving her with a broken nose and a neck injury.