He's had ups and downs in his young boxing career that could make anyone root for him. Diaz vacated his IBF lightweight belt to step up into a big money and big risk fight, as good fighters do. Most do not have to go up against boxing robot Jose Luis Castillo though. He put up a supremely game performance (showing the champion's heart) but ended up with a busted up face, an injured career, and a vicious boxing lesson. He's come back from an abyss that many boxers would not recover from. He's still here and still has his eyes fixed on the prize. He's a hardened warrior now, on a vengeful comeback trail, scorching through both of his post-Castillo opponents with first round knockouts. He's a smart, highly adaptive fighter and he possesses champion heart and focus. Julio Diaz has learned the hard way about what it takes to be on top. And Lord knows he is going to be a frightening opponent for any fighter who wants down that road.