The last Grand Slam event of 2021 was nothing short of history-making for the sport of women’s tennis.

The US Open took place in New York City, and on August 25, upcoming star Emma Raducanu played in the qualifiers. Battling opponent after opponent, she did not drop a single set and landed herself in the finals. This feat was incredible for many reasons.

First of all, before this summer, Raducanu had not played a single player ranked inside the top 100, and now she was about to play in the finals of a Slam. Raducanu also played the qualifiers, and then got all the way to the finals—a feat that had never happened before in the history of organized tennis.* On top of that, she had not dropped a single set during the entire tournament, gaining more than 100 ranking places and becoming British No. 1 on the way to becoming the first British woman to reach the US Open Final since 1968 Virginia Wade.

Now, after defeating Stefanie Vögele (currently ranked #841), Zhang Shuai (#8), Sara Sorribes Tormo (#34), Shelby Rogers (#40), Belinda Bencic (#9), and Maria Sakkari (#7), Raducanu faced Canadian Leylah Fernández for the title. If that wasn’t already an earth-shaking run, both Raducanu and Fernández are teenagers, both born in 2002, which made this the first US Open final in more than twenty years to feature two teens squaring off. (The last one was 1999, and the players were—you may have heard of them—Serena Williams and Martina Hingis.) As the match started, it was clear that Raducanu was not slowing down. After taking home the first set, the 18-year-old qualifier, who had ranked #150 in the world before this tournament, was only one  set away from victory. The pressure built up in the second set until finally, Raducanu came out with an ace to close the match.

Ten rounds and zero lost sets later, Emma Raducanu won the US Open and is now on track to become Britain’s richest sportswoman. The win also made her the first British woman to win a Grand Slam singles title since 1977. All was seemingly going perfectly for Raducanu, so it was very unexpected when she decided to fire her coach less than two weeks after winning perhaps the most prestigious tournament in tennis. Andrew Richardson had coached Emma for two years, and although it seems like it was certainly working, Raducanu had a different view. “I’m looking for someone who has been at that level and knows what it takes,” Raducanu said. Clearly, Emma feels like Richardson could only take her so far. She then said, “And especially right now because I’m so new to it, I really need someone to guide me who’s already been through that.”

Although the decision seems sudden and questionable, coaching relationships can go very wrong very quickly. At the top level, a coach is ‘hired to be fired’. The game changes from tournament to tournament, and in the end, it is up to the player to figure out what they think is best for them. If this US Open tells us anything, it’s that the future of women’s tennis looks bright, young, and talented.

* Ed. Note: The Morales couldn’t resist pointing out that Puerto Rican tennis star Monica Puig, who won gold at the 2016 Olympics in Rio de Janeiro, completed a similar feat: she was the first unseeded player in the modern era to take the gold.