The 23-time Grand Slam champion Serena Williams was stunned by Japanese Naomi Osaka in straight sets at the US Open 2018 final on Saturday. Serena ended up with runners-up trophy after losing 2-6, 4-6 to the 20-year-old in an hour and 19 minutes. Osaka, by the virtue of her victory in the final, became the first woman from Japan to win a Grand Slam title. Minutes before Japan's Osaka took the second set to win the title, Williams was involved in a verbal spat with the chair umpire Carlos Ramos. The umpire that warned the American for receiving coaching from her box. The conversation later saw Williams burst into tears eventually losing the second set as well.