India's Sania Mirza [Images], who only recently returned after a knee operation, blamed lack of match practice after losing 6-1, 6-4 to seventh-seeded Serb Ana Ivanovic in the second round of the French Open on Thursday.

The Indian number one underwent surgery in March after suffering a ligament injury in her right knee at the Qatar Open.

"I had surgery almost three months ago and this is my third tournament back," Sania told reporters.

Sania was outclassed in the first set but the second was a lot closer.

"I probably could have done a few things better but I guess that's where the lack of match practice comes into play," Mirza said.

She is one of her country's favourite sporting pin-ups after becoming the first Indian to claim a WTA title and reaching the top-50 in the rankings.

The world number 50 still has the doubles and mixed doubles to look forward.

"It has been a long process," she said of her comeback from injury. "We worked very hard in the gym the last couple of months.

"But I'm hitting the ball okay. Clay is not my favourite surface so I'm looking forward to the grass season."