Britain's Amir Khan is expecting a "crazy" atmosphere when he meets Mexico's Saul Alvarez in Las Vegas.
Former light-welterweight world champion Khan, 29, has not fought since outpointing Chris Algieri in May 2015.
But he has made a jump of two weight divisions to set up a WBC world middleweight title on 7 May, ruling out a meeting with fellow Brit Kell Brook.
"I'm going to the lion's den," said Khan. "If I beat him, it will be one of the biggest upsets in boxing."
"It's Cinco de Mayo as well, the Mexican holiday, so it's going to be crazy," he added. "I think it's brave and I think it's the right thing to do."
Khan said he wanted to fight multiple world champion Floyd Mayweather and seven-weight world champion Manny Pacquiao, but neither fights happened.
He added: "I want to be in the big fights with the big names. Alvarez I think is probably the biggest name in boxing right now.
"At first, I thought he was too big for me, but when I studied a few tapes, I thought: 'You know what, I've got a good chance of beating him'."
'I'm the underdog'
Bolton's Khan has won 31 and lost three of his 34 professional fights but has not won a world title after losing to Lamont Peterson in 2011.
He last fought at the MGM Grand in December 2014, beating American Devon Alexander on a unanimous decision.
"I've fought in Las Vegas three times, but normally I'm top bill," Khan told BBC Sport. "This time I'm the underdog. That will push me on even more.
"People are going to be doubting me, people are thinking it'll be an easy fight for Canelo, but he'll have his hands full."
'A 50-50 fight'
Alvarez, nicknamed 'Canelo', has lost once and won 46 of his 48 fights. That defeat came against Mayweather in 2013.
The fight has been set at a catch-weight of 155lb, eight pounds more than Khan weighed in victory against American Algieri.
The usual limit for middleweight is 160lb, but Alvarez's last few fights have had the same weight stipulation.
"When I announced that it was going to be Alvarez, everyone was shocked," said Khan. "That's what makes this fight bigger because it was a shock to everyone.
"What's going to win the fight for me is my skills and my speed.
"I don't think I can out-power Canelo. The only way I can beat him is my speed, skill and my techniques. I think it's a 50-50 fight."