Victor Ortiz has vowed to become the first man to defeat Floyd Mayweather Jr on September 17.
Ortiz will put his newly-acquired WBC welterweight title on the line when the pair do battle at the MGM Grand in Las Vegas.
'Vicious' Victor was trading as a 9/2 underdog when the fighters met at a New York press conference to announce the fight on Tuesday.
But despite that Ortiz, who stunned the previously-unbeaten Andre Berto in April to win the belt, is confident he can score an upset victory.
He said: "I have always said that I would be the first fighter to beat Floyd Mayweather and now that I have my chance, and to do it on a weekend that celebrates the independence of the Mexican people, is an amazing blessing for me.
"I have worked so hard to become a champion and to show the world that I am the best. I am not going to let anyone take that away from me.
"I'm confident that I will walk away from this fight with my belt and a new title...the first to defeat Floyd Mayweather."
Tags: Floyd Mayweather Jr. , Victor Ortiz , Mayweather-Ortiz , Mayweather vs Ortiz