MELBOURNE: Serena Williams' Australian Open ended with her ankle swollen to the size of a balloon, a spasming back and a quarter-final loss to a young pretender on Wednesday, a two week period that she described as the worst she had experienced at a grand slam.

“I'm almost relieved that it's over because there's only so much I felt I could do,” the 15-times grand slam singles champion said after her 3-6 7-5 6-4 loss to compatriot Sloane Stephens on Rod Laver Arena.

“Oh my gosh, it's been a little difficult. I've been thrown a lot of balls these two weeks.

“I've had a tough two weeks between the ankle, which is like this big every day,” she added gesturing with her hands. “And my back, which started hurting. A lot of stuff.”