World number one Ashleigh Barty has shocked the sporting world by announcing she will retire from professional tennis at just 25.
The Australian made the announcement on social media on Wednesday, saying she was leaving to "chase other dreams".
"I'm so happy and I'm so ready. And I just know at the moment in my heart, for me as a person, this is right," she said in a video.
Barty won her first Grand Slam at the 2019 French Open.
She has remained the top-ranked player since then, backed up by success at Wimbledon last year.
In January, she became the first home player to win the Australian Open men's or women's singles title in 44 years.
Serena Williams is the only other active female player to have won major titles on clay, grass and hard courts.
"I wasn't sure how to share this news with you so I asked my good friend [retired Australian tennis player Casey Dellacqua] to help me," Barty said on Wednesday.
"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 we created together."
Barty added she was "absolutely spent" and "physically I have nothing more to give".
Women's Tennis Association head Steve Simon said Barty was "one of the great champions" and would be missed.
"Ashleigh Barty with her signature slice backhand, complemented by being the ultimate competitor, has always led by example through the unwavering professionalism and sportsmanship she brought to every match," he said in a statement.
Fellow Australian Grand Slam winners also paid tribute. Sam Stosur hailed Barty's "incredible career", while Dylan Alcott said she was a "champion in every sense of the word".
Romanian former world number one Simona Halep added: "What's next for you? Grand Slam champion in golf?!"
Barty's Australian Open win had cemented her reputation as a national hero. In an emotional moment, she was presented with her trophy by fellow Aboriginal Australian tennis champion and mentor Evonne Goolagong Cawley.
A recent report by The Age newspaper highlighted how the number of Australian children playing tennis had climbed by nearly 30% in the past year. Many of them are from Indigenous communities and many are girls.
"I'm really proud that I can be a small part of getting more kids into sport and chasing their dreams," she told BBC Sport in January.
Barty took a break from tennis in 2014, citing its intense demands, and played in the inaugural season of cricket's Women's Big Bash League.
She said that was "a very different feeling" to her retirement on Wednesday, adding tennis had "given me all my dreams plus more".
Tamale SHS students empowered to fight against gender-based violence
Osimhen, Oshoala named African Men’s and Women’s Player of the Year at the CAF Awards 2023
2nd Food Safety Conference for Africa takes off tomorrow in Accra
Fameye and Black Sherif get ready to close 2023 ‘Victory Lap’
GIZ and SnooCODE partner to reduce e-commerce packaging waste in Ghana
At no stage has any broadcaster refused to pay fees – GIBA
Stars In Worship 2023: ‘My heart is now at peace’ – Akwaboah Jnr says as his father is honoured
Justice Sophia Akuffo, IEA urge Parliament not to ratify lithium agreement
MTN Ghana and GrowForMe unite forces to transform agriculture landscape for farmers
District Level Elections: Stay away, allow candidates campaign on their own merits – EC to political parties
Next NDC government will review laws governing extractive industry to benefit Ghanaians – Mahama
“We didn’t invest in making hiplife attractive to younger acts” – Okyeame Kwame
Mahama to lead sensitisation walk on ’24-hour economy’ on Dec. 21
Unlocking Prosperity: The 2024 RegTech Africa Conference Set to Redefine Data Governance for Growth
Seychelles plans to diversify its source markets in 2024