World No. 1 Naomi Osaka splits with coach after winning Australian Open

Feb. 11 (UPI) -- Top-ranked Naomi Osaka split ties with coach Sascha Bajin on Monday, more than two weeks after she won the Australian Open.

Osaka shared an unexpected tweet and announced her decision to end the duo's time together.

"Hey everyone, I will no longer be working together with Sascha," Osaka said. "I thank him for his work and wish him all the best in the future."

Bajin responded to Osaka and thanked her "for letting me be a part of this."

"Thank you Naomi. I wish you nothing but the best as well," Bajin said. "What a ride that was. Thank you for letting me be part of this."

The 21-year-old Osaka defeated Petra Kvitova in the Aussie Open final on Jan. 26, which was her second consecutive Grand Slam title. Osaka also won at the U.S. Open last September.

Osaka moved to No. 1 in the WTA rankings after her victory at Melbourne. The WTA named Bajin as the Coach of the Year in 2018.

The Japanese star hired Bajin before the 2018 season after he had previously worked with Serena Williams, Victoria Azarenka and Caroline Wozniacki.

Osaka withdrew from the Qatar Open this week with a back injury.