Stefanos Tsitsipas sends beautiful message to retiring great Serena Williams

Greek tennis player Stefanos Tsitsipas congratulated Serena on "an astonishing tennis career"

and urged her to return to tennis one day as Olympia Williams's coach.

In 2017, Serena and her husband Alexis welcomed their 1st baby, a baby girl Olympia Williams.

Serena is retiring after this year's US Open and Stefanos Tsitsipas made sure to send a beautiful message to the tennis legend.

"Hey Serena Williams, I'd like to congratulate you on a fantastic career," Tsitsipas told

"You're probably the only female tennis player that has aced me in a match so congratulations for that too - wasn't very entertaining for me!"

"Good luck on the next chapter of life, and make sure to return back with Olympia Williams as her coach one day," Stefanos Tsitsipas added.

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