Boston Celtics guard Isaiah Thomas doesn't make many look small on the basketball court. Not in the NBA, at least. But against 5'9" boxing champion Floyd Mayweather, it's a different story. Thomas visited Las Vegas to watch the WBA, WBC, and Ring welterweight champ train for his September 12 bout with Andre Berto. Cameras were rolling for Showtime's All-Access coverage of the fight. Ever the competitor, Floyd took the opportunity to challenge the Washington product to a game of hoops. It didn't turn out so well for Money.