This article traces the importation of prizefighting to Mexico in the nineteenth century. Boxing subculture in this era was an illegal, transnational, interracial, and culturally loaded practice that challenged Porfirian understandings of masculinity, race, and public spectacle. Pugilists violated legal prohibitions on prizefighting and created a context that energized the Mexican public sphere as a site of visceral debate about the propriety of prizefighting versus the Hispanic legacy of other blood sports and public spectacles such as cockfighting and bullfighting. Central here were explanations of what it meant to be a modern, culturally independent, and yet cosmopolitan nation. Deliberations about American influence were crucial in this period as Mexicans debated the meanings of growing American intervention in Latin America. Cultural practices such as prizefighting and lynching served as metaphors through which Mexicans discussed modernity, increasing flows of information, and novel options for cultural alignment.