Naomi Osaka has sensationally split with coach Sascha Bajin a little more than two weeks after she won the Australian Open and assumed the world No.1 ranking.
The 21-year-old Osaka, who won at Melbourne Park last month to add to her US Open crown from last year, announced on Monday that her successful partnership with Bajin had come to an end.
No reasons were given.
"Hey everyone, I will no longer be working together with Sascha. I thank him for his work and wish him all the best in the future," Osaka tweeted.
Osaka enjoyed a remarkable rise up the world rankings after she linked up with Bajin in the 2017 off-season.
The Japanese player climbed from world No.72 to reach the top five during the course of 2018, when she won her first grand slam title, and then hit top spot after her success in Melbourne.
Bajin, who has previously worked as hitting partner for Serena Williams, Caroline Wozniacki, Sloane Stephens and Victoria Azarenka, was named WTA coach of the year in 2018.
"Thank you Naomi I wish you nothing but the best as well. What a ride that was. Thank you for letting me be part of this," he responded to Osaka's tweet.