Five-time Grand Slam champion Maria Sharapova has admitted that her opponent Lucie Safarova was on a higher level to her in today's French Open fourth-round contest.

The defending champion failed to reach the quarter-finals as she succumbed to a 7-6[3] 6-4 defeat at the hands of the world number 13.

"My opponent had a different gear than I did," Sharapova told reporters. "I felt like I had small openings but I just wasn't able to play a good few points.

"She was able to do that for a longer period. She took the time away from me, created her angles and I didn't. That was the difference, in my opinion."

When asked if she felt as though her cold affected her performance, Sharapova said: "I don't like to talk about it, and I don't think it really makes a difference. I'm still a competitor, no matter what."

Safarova's quarter-final place at Roland Garros is the first of her career.