Forget the 38 major tennis titles, 22 Grand Slam singles championships and four Olympic gold medals — sometimes, all Serena Williams can remember is that she flubbed a couple of dance steps while performing for Beyonce in concert.

In an interview from today's (November 18) episode of The Ellen Degeneres ShowWilliams tries to explain the pressure of being a part of Bey's Lemonadeon which she famously appears as a "Sorry" feature. She says she felt particular responsibility to do Bey proud during an October Formation Tour stop in New York City, but that stress threw her a little bit off her game.

"It's a lot of pressure because you don't want to mess up," she said. "Bey's so great, she's such a wonderful performer and I've performed tennis-wise in front of thousands of people, but not, like, crowds that huge. So all I could think was 'Serena, don't miss your note, don't miss your note.' And what did I do? I missed my note."

Ultimately, though, Williams found her footing, and wound up having a little bit too good of a time.

"But then I was like 'This is so fun, I don't want to leave!'" she continues. "I was trying to stay out there an extra beat, but eventually they told me in my ear 'Serena, get off the stage!'"

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