Serena Williams' tennis coach says how proud he is of Stefanos Tsitsipas

Patrick Mouratoglou, the famous Greek-French tennis coach of Serena Williams since 2012 was extremely proud of Stefanos Tsitsipas's victory over Federer, having also trained him at his tennis academy when he was a teenager.

Mouratoglou speaking to Euronews after Tsitsipas' astonishing win against Roger Federer, said he has never had another player beat the world's former number 1.

"When you have a kid that grew up at your tennis academy and beats the best player of all times... it's impossible to describe."

He was extremely proud of the 20-year-old and even went on to say, "when you beat Roger playing like that... I think he can win [the Australian Open]." Moratoglou does not think it will be an easy task to beat current world number 2 Rafael Nadal, but he believes that Tsitsipas is mentally prepared.

The Mouratoglou Academy is located in Biot, in the French Riviera and was founded in 1996 by Patrick who always knew coaching meant the world to him.

"To make someone embrace their potential is the most significant accomplishment I could dream of." It is the biggest tennis academy in Europe and one of the best in the world because of its fantastic sports facilities and training methods.

In October 2017 on social media, Mouratoglou also posted, "Being half Greek, I am particularly happy and proud that my foundation Cham’Seed and Mouratoglou Tennis Academy have been part of that: Stefanos Tsitsipas is the first Greek player in the history to reach Top100 ATP. Fantastic achievement and a first milestone on a long journey that is just starting."