Sloane Stephens sends good luck "love note" to Madison Keys before US Open quarterfinal

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Besties supporting besties, we love to see it!

The 2017 US Open champion Sloane Stephens took to social media to share a sweet gesture in support of best friend and 2017 finalist Madison Keys, who will take on Marketa Vondrousova in the quarterfinals on Wednesday.

Stephens, who bowed out in the first round to Beatriz Haddad Maia, posted a few Instagram Stories as she dressed up in a new green Free People Movement kit for what appeared to be a photoshoot on Arthur Ashe Stadium.

She was there bright and early—the time stamp on one post read 6:51 a.m.—and she took advantage of the chance to leave a surprise for Keys.

“Ok, since I’m here I’m going to leave a little love note in Madi’s locker,” Stephens grinned in a video. “Hopefully she gets it after the match.”

Keys, the No. 17 seed, was due back on Arthur Ashe a few hours later to take on the reigning Wimbledon champion in the first match of the night session. After her 6-1, 6-4 victory, she revealed the note "just said she's basically rooting for me, proud of me, and just to keep going."

It was Keys' second Grand Slam quarterfinal of the year, as she booked a spot in the semifinals of a major for the first time since the 2022 Australian Open. It's been even longer since her last Grand Slam final—she faced Stephens in the final here six years ago—but Keys says she has learned to make peace with her up-and-down results as she gets back to her best tennis.

“I think that there's obviously been some really great highs and there's been some lows. When you're looking at people's careers, almost everyone has a year or two that are really tough,” Keys acknowledged in a US Open press conference.

“Being able to see the light at the end of the tunnel in those years and just keep the best perspective that you can during those years is the most important, because I think those are the years that can really feel like they're taking years off of your career.

“So [it helps] just having a better perspective of, I mean, if my worst year at my job is still traveling the world and playing tennis… Realistically it's not that bad.”

UPDATE: Keys found Stephens' note after knocking out Vondrousova in straight sets. Sloane might have to leave her bestie another one before she takes on No. 2 seed Aryna Sabalenka for the chance to reach her first Grand Slam final since 2017.