World tennis number one Ash Barty has made a shock call to quit tennis.
She retires from the professional game at just 25. The Australian superstar revealed on Wednesday via Instagram that she was "absolutely spent" and "physically I have nothing more to give".
"I'm so happy and I'm so ready. I just know at the moment in my heart, for me as a person, this is right," she said.
The announcement comes after Barty's three Grand Slam single wins, including this year's Australian Open in January – becoming the first home player to win the tournament's men or women's single in 44 years.
As the sporting world comes to terms with this loss, we look back at other celebrated athletes who chose to retire while at the top of their game.
American basketball player Michael Jordan is best known for leading the Chicago Bulls to six National Basketball Association (NBA) championships.
His unrivalled athleticism has been celebrated across the world, and at the time of his first retirement he was heralded a sporting megastar.
In 1993 he decided to quit basketball due to loss of appetite for the game, and a desire to end on a high. His father's death was also said to have been a contributing factor. He would go on to make a number of comebacks.
Jordan then retired again in 1995, 1998, and 2003.
Florence Griffith Joyner
American sprinter Florence Griffith Joyner, also known as Flo-Jo, was the star of the 1988 Olympics in Seoul where she won gold in the 100m, 200m, and 4x100m.
She set world records by running 10.49 in the US Olympic 100m trials to get to South Korea.
After the Olympics and during the height of her career she retired aged 29. Rumours of drug abuse followed the athlete throughout her career.
Ten years later she passed away after suffering an epileptic seizure in her sleep.
Olympic swimmer, Mark Spitz won seven gold medals in eight days at the Munich Olympics in 1972.
He set a world record in each of the four individual and three relay races that he entered. He also had 35 world records to his name. Aged just 22, Spitz retired.
In 2011 he said: "I retired because I didn't have a future in swimming.
"We couldn't make money. The rules were different back then compared to today".
In 1983 Swedish Björn Borg shocked the world when he announced he was bowing out of tennis at aged 26.
Borg retired at his peak, having won 11 major championships, an Open Era record at the time.
He also had six French Open titles, four of which were won consecutively between 1978-81.
After a frustrating fall at the US Open Final in 1983, Borg decided to hang his racket up for good – although he did attempt a comeback in 1991, 1992, and 1993.
The tennis world was shocked when world number one Justine Henin suddenly announced her retirement in 2008, aged 25.
She was best known for her wins at the French Open, where she won four of her seven Grand Slam titles between 2003 and 2007, she also won two US Open titles.
At the time of her retirement she was a two-time Wimbledon finalist. She suffered an elbow injury whilst playing against Kim Clijsters at Wimbledon, eventually forcing her into retirement in 2011.