Naomi Osaka has parted company with coach Patrick Mouratoglou less than a year after the pair began working together, the four-times Grand Slam champion said days after her defeat to Emma Raducanu at the Washington Open.

Naomi Osaka surprised a day ago by announcing the end of her coaching partnership with Patrick Mouratoglou after 10 months of working together. The four-time Grand Slam champion had not made the leap she expected with the French coach by her side,

Osaka's time with Mouratologou followed an up-and-down sequence of promising signs and frustrations with either injury or close-run defeats.