London - Gennady Golovkin and Saul 'Canelo' Alvarez's eagerly-anticipated bout will be watched by a global television audience, but it is not the only world middleweight title fight on Saturday.
Billy Joe Saunders's second defence of his World Boxing Organisation (WBO) belt against Willie Monroe Jr in London will not attract the same attention or glamour but is nevertheless significant since the winner is likely to face the victor of Golovkin-Alvarez clash, which takes place a few hours later in Las Vegas.
Golovkin, from Kazakhstan but based in California, defends the other three versions of the world title (World Boxing Council, World Boxing Association and International Boxing Federation) against Mexico's Alvarez in a clash between boxing's biggest stars now that Floyd Mayweather Jr has gone back into retirement.
For Saunders, there can be no more excuses about motivation after an inactive and frustrating reign as champion.
The 28-year-old English boxer won the WBO belt from Ireland's Andy Lee in December 2015 but due to injuries and postponements has only fought once since, an unimpressive points win over Artur Akavov at a leisure centre in Scotland in December.
But Saunders (24 wins, 0 defeats, 12 KOs) feels rejuvenated and credits new trainer Dominic Ingle with improving his conditioning ahead of facing American Monroe (21 wins, 2 defeats, 6 KOs).
"You can say lack of motivation but when you're in touching distance of something great, that alone gives me motivation," Saunders told reporters on a conference call from his training base in Fuerteventura, one of the Spanish Canary Islands.
"The way the Ingles go about their business is second to none. My fitness is on a different level. I'm fit enough now to fight 15 rounds, every minute of every round. That alone boosts my confidence by leaps and bounds.
"I know what is around the corner, I want to test myself against one of the greats. Willie had his chance (against Golovkin in May, 2015). I want to beat Willie Monroe in a better way than Golovkin did."
Golovkin, 35, and Alvarez, 27, are recognised as the best middleweights in the division and Saunders thinks the champion will prevail this weekend.
"I think it will be a very close fight but Canelo looks like he has overdone it in training, he looked fatigued in training and he's overdone it,' said Saunders, from Hertfordshire, northwest of London.
Saunders' promoter Frank Warren is confident his boxer will face the winner of Golovkin-Alvarez should he beat Monroe Jr.
"If Bill comes through he will fight the winner of Canelo-Golovkin," said Warren. "It's all in his hands now. He knows what he gets out of this fight if he wins and I believe he will deliver."
Monroe, 30, is boxing for the first time in a year and has registered two points-wins since being stopped in six rounds by knockout specialist Golovkin.
"He took a beating before and if he quit before when there were three belts on the line, he will certainly quit when there's one belt on the line," said Saunders.
Monroe, from New York, refused to be drawn into trash talk but is hoping Golovkin beats Alvarez so he can have a re-match.
"It's a shot at redemption," said Monroe. "I think Canelo is just going to win but I want Triple G (Golovkin) to win so I can get him back.
"If you look at my fight with Golovkin and his fight against Kell Brook and Danny Jacobs, he doesn't deal with fast fighters.
"I've had a 12 week camp for Billy Joe, but I only got six weeks' notice for Golovkin. I never had big backers and money guys in my corner to make things happen, so when a shot like that comes up you take it."
He added: "Billy Joe has had a great promoter like Frank Warren in his corner. All the fights have been in his own backyard.
"He hasn't had to go into a lion's den with all these screaming fans against him."