Serena Williams' ex-coach, Patrick Mouratoglou, has weighed in on why Aryna Sabalenka is now ready for more Grand Slams following her win against Amanda Anisimova in the US Open final.Sabalenka competed in the US Open final on September 7, 2025, where she triumphed over Anisimova in a thrilling showdown, registering a 6-3, 7-6(3) win. This victory marked the World No.1's first Grand Slam triumph of the season, after she fell short of claiming titles at the Australian Open, French Open, and Wimbledon.Days after her triumph at the Arthur Ashe Stadium, the Belarusian's game was analyzed by Williams' former coach, Mouratoglou, who opened up about her last two Grand Slam upsets that fueled her to gain victory in the US Open and how losing it would have affected her career.Calling it a 'huge challenge' for Sabalenka, the coach said that this match was the 'most important' one of her career."I think this final of the US Open for Sabalenka was probably the most important match of her career, because if this would have happened again, it would have probably affected her future. Now the fact that she has been able to correct what went wrong in the last two finals to win this one is an incredible victory for her. And that’s also why she was so emotional after winning, because she turned two mental disabilities to win a Grand Slam final into an incredible ability to win this one," said Mouratoglou.He further said that it was also a big challenge for Aryna Sabalenka, as she was competing against Anisimova, and praising the latter's skills on court, he added:"It was a big challenge also because on the other side of the court was Anisimova, American in the US. Nothing to lose and playing incredible tennis. And if you look at the start of the match, she starts like a bomb. Anisimova starts with winners all over the place, which creates a feeling of insecurity even much higher. For Aryna, the challenge in that final was even bigger than anyone can think of." View this post on Instagram Instagram PostAryna Sabalenka sent a playful warning to Nick Kyrgios ahead of their 'Battle of the Sexes' clashAryna Sabalenka recently appeared on the Jay Shetty podcast, where she spoke about her upcoming Battle of the Sexes match against Nick Kyrgios in 2026. She sent the latter a playful warning, asking him to get ready for their clash."Well, Nick, you gotta be ready. You'd better be ready. Yeah.. I'm gonna kick your a** man. I think the ATP is gonna cancel the battle. They'll be like, ok, if it's happening, let it be Jannik or Carlos, but not Nick," Aryna Sabalenka said laughing.A few days ahead of this, the Aussie also spoke about his clash against Aryna Sabalenka during his conversation with Alexander Bublik. Exuding confidence in himself, Kyrgios said that the World No.1 would not be able to defeat him in their match.