When Caty McNally took the court Wednesday night at Arthur Ashe Stadium, she tried not to overthink who her opponent across the way was, even though it happened to be Serena Williams.

“I just try to take it as another match and not really worry about who’s across the net,” McNally said at the US Open. “I know if I did that, it might affect the way I play. I might become more emotionally attached to the match. That’s not good for me.”

McNally stuck to that mentality as she stunned Williams in the first set, 7-5. The 37-year-old veteran went on to defeat McNally, taking the final two sets 6-3, 6-1 against the rising 17-year-old tennis star in the second round.

“I’m really just happy with the way I overall played, the way I carried myself out on that stage,” McNally said. “I walked out there, and I had the chills. That was the most insane atmosphere. I’ve never played on a court nowhere near that big, especially a night match. I couldn’t have asked for anything better. It was just an unbelievable experience, something that I’ll never forget for the rest of my life.”

Ranked No. 111 in the world, the Cincinnati native made her WTA main-draw debut in 2017 at the Western & Southern Open playing doubles with Alexa Glatch. In 2018, McNally won two doubles grand slam girls titles — the French Open with Iga Swiatek and the US Open with Coco Gauff.

McNally is coached by her mother, Lynn Nabors-McNally, who played at Northwestern and is a prominent coach in Ohio. Her brother, John, is also an aspiring tennis player and nervously watched Caty battle Williams on Wednesday night.

“That’d be insane, but you never know,” John told the Desert Sun in 2016, when asked about the possibility of both making it professionally. “We both dream of like playing mixed doubles at the US Open or doing something awesome like that. My parents would love to see that too, obviously.”

On Monday, McNally defeated Swiss tennis player Timea Bacsinszky in the first round. And though her journey this time around has come to an end, McNally is grateful for her experience against Williams.

“I was just really excited, honestly,” she said. “Could you tell from my reaction? I was really pumped up. Super happy just to get a set from her. That’s something that not very many people do. But I knew I needed to stay focused because I knew she was going to pick up her level.”