Shingo Kunieda, the world No.1 wheelchair singles player, is hanging up his racquet.
The Japanese 38-year-old announced his decision on Sunday, closing the book on an illustrious career in which he amassed 28 Grand Slam singles titles, 22 Grand Slam doubles titles and a smattering of Paralympic medals.
"I've been thinking about retirement since my dream came true at Tokyo Paralympics," he wrote in a social media post.
"Last year, Wimbledon singles title for the first time made me feel that my energy was little left to compete.
"By capturing the 10th time world champion, I felt that I have done enough in what I wanted to accomplish and thought it was the right time to retire."
Seventeen years since reaching the world top ranking, Kunieda is stepping back from the sport as the reigning world No.1 and won't defend three of the four major titles he won last year.
In singles, Kunieda boasts 11 Australian Open crowns, eight titles at both Roland Garros and the US Open, in addition to a sole Wimbledon triumph.
He's also been a dominant force in the major doubles scene, with eight titles at both the Australian Open and Roland Garros, four Wimbledon trophies and a pair of US Open crowns to his name.
His Grand Slam tally of 50 is unrivalled by anyone in the men's game.
Away from majors, Kunieda is remarkably decorated.
After earning a Paralympic wheelchair doubles gold medal at Athens 2004, he won singles gold at Beijing 2008, London 2012 and Tokyo 2020, where he was an ambassador.
A pair of bronze doubles medals from Beijing 2008 and Rio 2016 round out his collection.
"Truly extraordinary wheelchair tennis life for me," Kunieda wrote on Sunday.
By winning the Wimbledon 2022 crown last July, Kunieda became the first male wheelchair tennis player to clinch a career Grand Slam.
"It was one of the most tough match in my career," he said of his thrilling three-set victory over Alfie Hewett.
"You know my age, 38, so I was thinking it will be my last chance today," he said, providing a glimpse into a future that doesn't include tennis.
Kunieda revealed that advice from another all-time great helped him lift the coveted Wimbledon trophy, which he ranks as a career highlight alongside his Tokyo 2020 gold medal.
At an event in 2021, Kunieda had the ear of eight-time Wimbledon champion Roger Federer.
"My question was how to play on grass, and how to think when behind on grass," revealed Kunieda.
"He said, yeah, you should attack every point. If you [make a] mistake, no regrets. That's the key."
Paralysed by a spinal tumour at the age of nine, Kunieda played both wheelchair tennis and basketball before choosing tennis, becoming Japan's first professional athlete focused on the sport.
To say he's been successful would be an understatement. Kunieda redefined dominance with a mind-blowing 107 consecutive matches between 2007 and 2010. A national hero in Japan, Kunieda has been featured in an anime series in his homeland.
Passionate about his craft, the 38-year-old has channelled his energy into inspiring the next generation of wheelchair tennis players.
"During my 20 year career, I could notice lots of improvement in the wheelchair tennis, such as all the Grand Slams now offering us to play, or the prize money increase in the tour," he said.
He credits the ITF for its oversight of both wheelchair and able-bodied tennis.
"I am hoping for more improvement to come so that wheelchair tennis can continue to grow," he added, urging fans to continue supporting the sport.
Kunieda's historic career has left a lasting impression on his peers.
"For me he's the greatest player of all time," Australian wheelchair tennis player Ben Weekes said.
Australian quad wheelchair world No.5 Heath Davidson described Kunieda as an "all round good bloke".
"I wish I had as many achievements as him, it's unbelievable," Davidson said.
"He's done so much for the sport, he's the guy who made all of us be professional wheelchair athletes.
"He did everything on and off the court properly: diet, training, resting, [and had a] huge impact. Definitely an idol of mine.
"They talk about Rafa, Novak and Federer being the GOAT…I understand it's a bit different but 50 Grand Slams is pretty good."