Simona Halep has revealed that she fought through the pain barrier to defeat Sabine Lisicki in her fourth-round clash at the US Open.

The number two seed was forced to come from a set down to beat the German to book her place in the quarter-finals, and the Romanian has conceded that she was far from her best as she struggled with cramp during the contest.

Halep told reporters: "I didn't play my best, but I played good enough to win. It was a very tough match, just as I expected. I am very happy I could win.

"At one point my back was cramping, then the leg was worse. I do still feel pain, but tomorrow I have a day off and thus I have time to recover.

"I really hope I am going to be okay to play the next match. It will be tough, but at this point I feel like I have nothing to lose, so I am just going to go on court and enjoy the match."

Halep will face Victoria Azarenka in the last eight of the competition.