Serena Williams is summer ready!

The 35-year-old tennis star shared a sexy bikini photo on Instagram on Friday. Her reason? "Just because."

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The snap features Williams posing in a slinky yellow two-piece while showing off her rock-hard abs and amazing biceps.

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Naturally, Williams' fans were drooling over the pic, and some even took the sultry snap as gym motivation.

"I hope to look this good one day," wrote on a commenter while another added, "I got to start working out @serenawilliams after seeing your abs."

"Gonna start playing tennis," promised another fan.

Others complimented Williams on her beauty, dubbing her "spectacular" and a "beautiful black queen."

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Williams may be flaunting her bikini bod, but she'll be rocking a more formal look for her upcoming wedding to Reddit co-founder Alex Ohanian. The couple announced their engagement in December with Williams sharing a heartfelt post on her Reddit account.

"I came home. A little late. Someone had a bag packed for me. And a carriage waited. Destination: Rome,"she wrote at the time. "To escort me to my very own 'charming.' Back to where our stars first collided. And now it was full circle. At the same table we first met by chance, but by choice.

"Down on one knee. He said 4 words. And I said yes," Williams added.