SYDNEY - World number one Ashleigh Barty stunned tennis on Wednesday by announcing her retirement from the sport aged just 25, saying she had fulfilled her dreams and was “spent physically”.

Barty dropped the bombshell weeks after becoming the first home Australian Open champion in 44 years and so winning a Grand Slam crown on three different surfaces. In a tearful social media video message with her close friend and former doubles partner Casey Dellacqua, Barty said she was “so ready” to call it quits after achieving her life-time ambition to win Wimbledon last year.

“Success for me is knowing that I’ve given absolutely everything, everything I can. I’m fulfilled, I’m happy and I know how much work it takes to bring the best out of yourself,” said the three-time Grand Slam winner. “It’s just I don’t have that in me anymore. I don’t have the physical drive, the emotional want and kind of everything it takes to challenge yourself at the very top level anymore.

“I think I just know that I’m absolutely, I am spent. I just know physically I had nothing more to give and that for me is success.” One of the most respected and loved players on tour, Barty also became the best -- with her dizzying array of slices, pinpoint serving and seamless forehand typifying her all-round game.