(CNN) World No. 1 Ashleigh Barty has shocked the tennis world by announcing her retirement from the sport after winning three major singles titles in the last three years.
"Today is difficult and filled with emotion for me as I announce my retirement from tennis," the 25-year-old Australian said in the caption of an Instagram post 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 that we created together."
The post included a video, filmed with retired Australian tennis player Casey Dellacqua, in which Barty further explains her decision.
"There was a perspective shift in me in the second phase of my career, that my happiness wasn't dependent on the results, and success for me is knowing I've given absolutely everything I can," she said.
"I know how much work it takes to bring the best out of yourself. I've said it to my team multiple times, it's just I don't have that in me anymore. I don't have the physical drive, the emotional want, and everything it takes to challenge yourself at the very top of the level anymore, and I just know that I am spent. I just know physically, I have nothing more to give. That, for me, is success."
She added that she had been thinking about retirement for "a long time," and the decision was cemented after winning Wimbledon last year and the Australian Open this year. Those victories were "my perfect way to celebrate what an amazing journey my tennis career has been," she said.
The decision was difficult but felt right, she said. "Ash Barty, the person, has so many dreams that she wants to chase after that don't necessarily involve traveling the world, being away from my family, being away from my home, which is where I've always wanted to be."
The Women's Tennis Association (WTA) confirmed her retirement in a news release.
"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," WTA chairman and CEO Steve Simon said in the release.
"With her accomplishments at the Grand Slams, WTA Finals, and reaching the pinnacle ranking of No.1 in the world, she has clearly established herself as one the great champions of the WTA."
Barty has won three major singles titles -- the 2019 French Open, the 2021 Wimbledon and the 2022 Australian Open. In total, she has won 15 singles titles and 12 doubles titles on the WTA Tour, and was the first Australian to win the Australian Open singles title since 1978.
She is only the second reigning World No. 1 in the women's game to retire at the top, following Justine Henin, who retired in 2008.
Barty, who started her professional tennis career in 2010, took a break from the sport from 2014 to 2016, saying "it was too much too quickly," according to the WTA release. Only 18 at the time, she wanted to "experience life as a normal teenaged girl," she said.
She returned to tennis full-time in 2017 -- and went on to dominate the sport, winning 25 of her last 26 matches.