Osaka Naomi, the daughter of a Japanese mother and a Haitian father, won the U.S. Open on Saturday in New York City. It was a big victory for the 20-year-old. She is the first Japanese athlete to win a tennis Grand Slam title, and she was playing her idol, Serena Williams, in the final. Williams is one of the greatest players in the history of tennis. She has more singles titles than anyone else except Margaret Court. However, Williams had to take time off last year when she had a baby. Williams played hard as usual, but she couldn’t keep up with Osaka, who is 16 years younger than her.