NEW YORK -- Welcome back to the US Open, Serena Williams.

Williams, a 23-time Grand Slam singles champion, returned to Flushing Meadows on Saturday -- but she was watching tennis, not playing it.

And she brought back an old look, wearing a denim skirt similar to the one she sported while competing in New York in 2004.

This was the first visit to the US Open by Williams since 2022, when she played there in the final tournament of her career. She made it to the third round then before losing to Ajla Tomljanovic in her last match, although Williams was careful not to say she was retiring, but rather described it as "evolving" away from professional tennis.

She has been plenty busy ever since, pursuing her business interests, signing a book deal, putting out a documentary series currently airing on ESPN and, in July, hosting the ESPYS. Williams gave birth to her second daughter a year ago.

The 42-year-old American won six singles championships at the US Open -- tied with Chris Evert for the most -- during her decades of dominance with a racket in her hands. This time Williams was sitting in a suite in Arthur Ashe Stadium while Jannik Sinner, the No. 1-ranked man, earned a straight-sets victory in the third round against Christopher O'Connell.

Williams made her way around the grounds, checking out American Tommy Paul's win at Louis Armstrong Stadium and stopping by the players' gym at one point for a chat with the current women's No. 1, Iga Swiatek, who was scheduled to play on Saturday night.

One of Williams' good friends, 2018 Australian Open champion and former No. 1 Caroline Wozniacki, joked after winning Saturday to get to the fourth round that she was disappointed not to have spotted Williams in the spectator seats on the Grandstand.

"I'm going to text her," Wozniacki said with a laugh. "I'm pretty mad at her for not showing up at my match. ... I think we have to talk about that a little bit later."