SERENA WILLIAMS claimed she was “almost relieved it’s over” after an injury-plagued Australian Open campaign ended at the hands of teenage prodigy Sloane Stephens.

Williams suffered a twisted ankle in her opening-round whitewash of Edina Gallovits- Hall and then saw her hopes of advancing to a semi-final meeting with Victoria Azarenka compromised by a lower back problem sustained in the second set.

At the time, she was in front and looking good to secure a place in the last four in Melbourne for the sixth time, but Stephens made the most of her good fortune to go through 3-6 7-5 6-4.

Asked if it was the worst two weeks she had ever had at a grand slam, Williams said: “At a grand slam, absolutely.

“I’m almost relieved it’s over because there’s only so much I felt I could do.

“It has been difficult. I have been thrown a lot of balls this week.”

To focus solely on Williams would be unfair on Stephens, however.

The 19-year-old from Florida showed remarkable poise in her first grand slam quarter- final to come through against her fellow American and childhood hero.

Having admitted to some pre-match doubts, Stephens revealed she gave herself a pep talk to restore some belief.

She said: “When I got up this morning I was like, ‘look dude, you can do this – go out and play and do your best’.’’ Current world number one Azarenka earlier beat Svetlana Kuznetsova 7-5 6-1 to keep the defence of her title on track.

Kuznetsova, a two-time former grand slam champion, proved she is over the knee surgery which forced her to miss the second half of 2012 with a wonderfully creative display – mixing clever angles with raw power.

But it was not enough to derail Azarenka, who, having edged the first set, ran through the second to register her 12th successive win in Melbourne.