Stunning news emerged from the tennis world Tuesday when Ash Barty announced her retirement.

The 25-year-old Aussie has stood atop the WTA's rankings since Sept. 9, 2019.

Barty explained her decision in a six-minute interview posted to her Instagram page. The post also contained this note:

"Today is difficult and filled with emotion for me as I announce my retirement from tennis. I wasn't sure how to share this news with you so I asked my good friend @caseydellacqua to help me. I am so thankful for everything this sport has given me and leave feeling proud and fulfilled. Thank you to everyone who has supported me along the way, I'll always be grateful for the lifelong memories that we created together. More to come tomorrow at my press conference."

Lindsay Gibbs of Power Plays transcribed and relayed some of Barty's comments:

Barty is a three-time Grand Slam singles winner with victories in the 2019 French Open, 2021 Wimbledon and 2022 Australian Open.

She sports a career record of 305-102, including a perfect 11-0 mark this year. Barty's last match was a win over Danielle Collins in the Australian Open final.

Overall, Barty won 15 WTA singles titles and 12 doubles titles.

Barty endured a difficult stretch during the 2021 season.

After losing in the final of the Madrid Open, she suffered an arm injury during an Italian Open quarterfinal match in May.

A hip injury forced her out of the French Open in the midst of her second-round match three weeks later.

She returned in late June to compete at Wimbledon, and she defeated Karolina Pliskova on July 10 to win her first title at the All England Lawn Tennis and Croquet Club.

In January, Barty won the Australian Open, but physical ailments forced her off the court again.

She released a statement in early March explaining her decision to pull out of two tournaments, per the Australian Associated Press (h/t Yahoo Sports):

"I wanted to share an update on my schedule for the coming months. Unfortunately my body has not recovered the way I'd hoped after the Australian Open and I have not been able to adequately prepare for Indian Wells and Miami. I don't believe I am at the level necessary to win these events and as a result I have decided to withdraw from both tournaments. I love these events and am sad not to be there competing but getting my body right must be my focus."

Now Barty has decided to leave the game for good, and she ends her career as the best in the sport.

Many analysts and reporters applauded Barty as she stepped away:

Barty won three of the last four tournaments she played, including the Australian Open, the Adelaide International and the Western & Southern Open.