(NEW YORK) — Twenty-year-old Naomi Osaka faced her childhood hero Serena Williams in the 2018 U.S. Open Women’s Final and won, becoming the first Japanese woman to win a Grand Slam title in a match that many thought would go to Williams.Her triumph, however, was marred by arguments between Williams and the match’s umpire, Carlos Ramos, sparking a controversy that would have the world talking about tennis for weeks.As part of the new ESPN series Backstory, Pulitzer Prize-winning journalist Don Van Natta peeled back the layers of the event and delved into the lives of both Williams and Ramos to understand how the two came together for one of the most divisive moments in recent tennis history during one of the world’s most celebrated finals in sports.Ramos was only 16 when he began working as a chair umpire in Portugal. One of his friends told Van Natta that Ramos was so focused that he would treat satellite events as if they were the Wimbledon final. But Ramos had big dreams of one day becoming a world-class umpire, a goal that he said would allow him to see the world, Van Natta said.Williams and her sister, Venus Williams, meanwhile, would rise out of Compton, Calif., to become two of the biggest sports stars in the world by dominating a sport played mostly by white athletes.With her fierce will to win, Williams did not get to the top without shaking things up. In May 2018, for example, she received criticism for wearing a so-called “catsuit” bodysuit to the French Open. She said the suit was designed to prevent blood clots since she had given birth a few months earlier. French Open President Bernard Giudicelli later said the suit “would no longer be accepted” and that players in future tournaments would have to dress more conservatively.The heated dispute between Ramos and Williams, who was vying for a record-tying 24th Grand Slam singles title, began when Williams was losing to Osaka two games into the second set after Ramos said he witnessed a code violation for coaching — Williams’ coach, Patrick Mouratoglou, had given her a thumbs up — and gave Williams a warning.“If he gives me a thumbs-up, he is telling me to come on,” Williams told Ramos at the time. “We don’t have any code and I know you don’t know that, and [I] understand why you may have thought that that was coaching, but it is not. I don’t cheat to win; I would rather lose. I am just letting you know.”Retired tennis champion Chrissie Evert told Van Natta that Mouratoglou, who has coached Williams for seven years, “is not known to be one of those coaches who coaches all the time and Serena never looks at her box. She…figures it out herself.”From that moment, the tension between Williams and Ramos would escalate. Williams accused Ramos of questioning her integrity and punishing her more harshly than male players. “I have a daughter and I stand for what’s right,” she told him. “I have never cheated.”A second violation, costing her a point, came after the fifth game of the second set when she slammed a broken racket to the ground in frustration. After repeatedly demanding that Ramos apologize, she received her third violation for what Ramos called “verbal abuse” — a game penalty — after she called him a “thief.”“You stole a point from me,” she said. “You’re a thief, too.”Although Williams would go on to win the next game in an excellent display of tennis, Osaka would finish her off in the ensuing match, winning the set and the title.Mouratoglou told Van Natta that it was the first time he had ever sent a signal to Williams and that he did it “because it felt like it was an important moment.”“It was probably one of the biggest moments of her career,” Mouratoglou told Van Natta. “She’s in a Grand Slam final to equal the record of all time and she’s losing, and she’s — I [felt] at that moment — she’s lost on the court. So, I tried to help her. That’s my job.”Yet, even though the incident was a setback for Williams, Mouratoglou said that it was a “fantastic” moment for tennis.“It’s unbelievable. That was the best moment of tennis [in the] last 10 years,” he told Van Natta. “We don’t have any drama in tennis. We have drama in all other sports, but not tennis.”Williams gave Osaka a congratulatory hug following the match, but as the crowd booed, Osaka sat down and cried.“I was down on the court because I was supposed to present the trophy to the winner,” Evert told Van Natta. “The floor was shaking, the roof was shaking, the boos were thundering. I could not hear a thing.”Williams continues to deny that there was a clear coaching violation or that she ever lost control of her emotions, Van Natta said. In a press conference following the match, she said, “The fact that I have to go through this is just an example for the next person that has emotions and that wants to express themselves…they want to be a strong woman and they are going to be allowed to do that because of today.”Copyright © 2019, ABC Radio. All rights reserved.