Coco Gauff’s decision to bring on Gavin MacMillen as her new coach seems to be paying off. Her mom, Candi, even gave him a big hug after Coco’s thrilling first-round win over Ajla Tomljanović.

Coco, 21, defeated Tomljanović 6-4, 6-7(2), 7-5 in a nearly three-hour match at Arthur Ashe Stadium. After the match, Coco commented, “It was a tough match. I had a chance to make it a straight set. It wasn’t the best, but I’m happy to get through to the next round. I had so many chances. Eventually they will come. Eventually one of these will go my way. It happened in that game.”

When asked about her coaching change and the focus on her serve, she added, “It’s an improvement from Cincy last week. I’m trying to improve with each match.”

In other news, Naomi Osaka also advanced to the second round, easing past Greet Minnen on Louis Armstrong. Osaka and Gauff are among only six active women with multiple Grand Slam singles titles, and together they’ve won three of the past seven US Opens. Each captured a second major at the precocious age of 21. For more highlights and scores visit us Open.org.