Though Bianca Andreescu was expected to be a formidable opponent, it was Serena Williams who was favored to win the US Open Tennis Championships finals in New York City on September 7, 2019. The 37-year-old US tennis phenom is after all an experienced veteran, with 23 Grand Slam titles to her name. Meanwhile, prior to 2019, her 19-year-old challenger had never even reached the finals of the four prestigious tournaments — the US Open, the Australian Open, Wimbledon and the French Open — that comprise the Grand Slam. But in a true-life underdog story, Bianca managed to oust Serena with a resounding 6-3, 7-5 victory in less than two hours.