Kim Clijsters blamed a loss of confidence for her shock second-round defeat by Arantxa Rus at the French Open while Maria Sharapova admitted she was lucky to avoid joining the Belgian in making an early exit.

Second seed Clijsters, who was going for a third consecutive grand slam title, looked in control at a set and 5-2 up but she missed two match points and from there it was all downhill as Rus won 11 of the last 12 games to triumph 3-6 7-5 6-1.

Asked to explain her dramatic slump, Clijsters said: 'I'm still trying to figure that out. I felt kind of in control. I felt like she was missing quite a lot at the beginning of the rallies, and I felt that I was moving her around well from side to side.

'Then I started doubting a little bit. I think, on clay, that is something that for me is definitely the wrong attitude to have.

'She obviously started building up more confidence, started playing a lot better and was really putting me on my back foot all the time. I couldn't really play my aggressive tennis anymore in that third set.'

Clijsters was playing at the French Open for the first time since 2006 and in her first tournament of any kind since March following an ankle injury sustained at a cousin's wedding.

The Belgian refused to blame that for her loss, though, saying: 'My ankle feels fine, so that has absolutely nothing to do with it.

'I made the best of the situation that I was in and I tried to go for it. If I felt like I wasn't ready as much as I would have liked to be, I wouldn't have come here.'

Clijsters was a major doubt for the tournament because of her lack of preparation but she insisted she had no regrets about her decision to play in Paris.

'I'm happy that I did that, that I gave myself the opportunity,' she added. 'It's better to try than not to try, that's my attitude. I'm not going to sit here and say maybe I shouldn't have come here. That's the attitude of a real loser I think.'

Rus, through to the third round of a grand slam for the first time, described the victory as the biggest of her career.

The 20-year-old, who is ranked outside the top 100, said: 'This is for sure my biggest win. It was really nice to play against her. She's a real hero. I played fantastic tennis.'

Sharapova looked in severe danger when she trailed 17-year-old Caroline Garcia by a set and 4-1, but the Russian is renowned for her fighting qualities and she did not lose another game in a 3-6 6-4 6-0 victory.

The French crowd were going wild at the exploits of world number 188 Garcia, who was playing so well that Andy Murray and Martina Navratilova both declared she would one day be world number one.

Sharapova said: 'It could have easily gone the other way today but I think I knew I had to make an adjustment. I just never think that the match is over until it actually is.

'I never really felt comfortable throughout the match. I was just really trying to find my own rhythm. More than anything I was trying to be more consistent and make her hit the errors instead.'

Sharapova was more guarded in her assessment of Garcia's prospects, saying: 'I think time will tell. It's a long road. It's tough for me to tell but she's on her way up, definitely.'

Garcia hopes she will be able to live up to Murray and Navratilova's prediction, and she said: 'I have this dream. It's very difficult but I hope one day I will be number one. My future is full of promise but I also realise I need to work a lot.'

Garcia admitted she was affected by thoughts of what she might achieve but credited Sharapova for turning the match around.

She added: 'I had many things in my head because I was leading. I was playing well. She was not really in the match. And then she reacted like a champion, because she is a great champion.

'I started becoming very nervous and I started playing more from the baseline, and it was difficult for me to come back.'

It was a different story for fourth seed Victoria Azarenka, who blitzed Pauline Parmentier of France 6-0 6-1 and is looking like the woman to beat in the bottom half of the draw.

Sixth seed Li Na and ninth seed Petra Kvitova were also straight-sets winners, with the Czech in particular looking like someone who could prove a real threat next week.

Agnieszka Radwanska, Andrea Petkovic, Yanina Wickmayer, Kaia Kanepi, Maria Kirilenko, Jarmila Gajdosova and Roberta Vinci were all winners but 27th seed Alexandra Dulgheru was dumped out by fellow Romanian Sorana Cirstea.