World No 1 Naomi Osaka has split from her coach Sascha Bajin.

The 21-year-old, who won the Australian Open last month and the US Open last year, announced on Monday that their successful partnership had come to an end.

No reasons were given.

World No 1 Naomi Osaka has announced she has split from her coach Sascha Bajin

With Sascha Bajin as her coach, Osaka won the Australian Open and went to world No 1

Osaka tweeted: ‘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 enjoyed a remarkable rise up the world rankings after first linking up with Bajin in the 2017 off-season. The Japanese player climbed from 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.

He responded to Osaka’s tweet by replying: ‘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.’

The rediscovery of Mark Wood’s 90mph magic comes at the end of a Test winter in which he has reconfigured his approach to the crease.

The 29-year-old’s enigmatic career took in a significant spike in fortunes this week when he was unleashed from his new longer run-up for the first time in Tests and took a maiden five-wicket haul against West Indies.

However, the exhilarating performance in St Lucia was not an overnight success but several months in the making, following extensive work with England bowling coach Chris Silverwood on the one-day tour of Sri Lanka last autumn. 

The rediscovery of Mark Wood’s 90mph magic comes after changing his run-up

The 29-year-old unleashed from his new longer run-up for the first time in Tests

Silverwood encouraged the Durham man to ditch the distinctive push-off from a standing start — which he had used since boyhood, through multiple ankle operations — in a bid to reduce stress on his body.

The alterations are not a failsafe against further injury, and his splayed front foot still puts pressure on his susceptible joint, but building up momentum over a longer distance has returned Wood’s confidence in his body’s ability to produce pace in excess of 90mph over an entire spell.

Although the extension means he has lost some of the explosion through the crease that was previously thought to be key to generating his maximum speeds — he still believes his spell on Twenty20 finals day in 2016, when Joe Root said he made him feel like he had his hands on the wrong way round, is the fastest of his career — it has also rid him of occasional jerkiness that slowed him down on occasions.

The challenge now is for the England side to use it effectively in a year they have ambitions of both World Cup and Ashes glory.

Wood took a maiden five-wicket haul against West Indies on day three of third Test