Floyd Mayweather Jr. vs. Conor McGregor On this day, in 2017 Mayweather extended his pro boxing undefeated streak to 50 victories , surpassing Rocky Marciano, after defeating McGregor by a 10th round TKO. August 26, 2017 Sport: Boxing Trivia Which Nations Won the Gold, Silver and Bronze Medals the Last Time Baseball Was an Olympic Sport? What Are the Five Events That Make Up the Modern Olympic Pentathon? sports in this article Boxing tags in this article Fan On This Day SportsEngine