Andy Ruiz Jr. admits he was 'half-assing' career after becoming champion: 'I thought I knew it all'

Seven years after springing one of the biggest upsets in boxing history, the Mexican Rocky is back with his old trainer for one final run at the heavyweight summit Seven years ago, Andy Ruiz Jr became the first fighter of Mexican descent to win the world heavyweight championship…

Ruiz Jr., boxing's first-ever heavyweight champion of Mexican descent, has worked hard to overcome the regret he felt for not maximizing his opportunities after an upset win over Anthony Joshua.