I'll start by acknowledging that--before Svetlana Kuznetsova's second round French Open match began--I was expecting an upset. Once it got underway, I was expecting an upset even more. And then, serving at 6-4, 5-3, 40-0, Petkovic saw four match points--and the match--fade away. 6th seed Kuznetsova saved the first match point with a strong return, but the other three were the unforced errors of a player with insufficient experience in handling really big moments. When you're at a major, about to beat the defending champion, in straight sets--the belief that you cannot do it is playing in your unconscious mind like a song you don't realize you're humming. Kuznetsova broke, and went on to win the second set, and that was that. Her 4-6, 7-5, 6-4 victory--a gift from a choking opponent--places her in the third round against countrywoman Maria Kirilenko.
Then there was Madrid champion Aravane Rezai, who apparently became so anxious in the second set of her match against Angelique Kerber that she set up a number of winners, only to commit repeated unforced errors when she attempted to execute them. But Rezai put that set behind her, and won the third set, posting a 6-2, 2-6, 6-3 score. It was a messy match for her--she made 42 unforced errors. She also hit 59 winners.
Taking out the 24th seed may not sound like a big upset, but when the match is played on clay, and it's 2010, and the opponent is Lucie Safarova, the upset is kind of a big deal. It was pulled off by the steadily rising Palona Hercog, who defeated Safarova 6-1, 6-2.
All of the other seeds advanced. Of interest: Chanelle Scheepers defeated Gisela Dulko 3-6, 6-3, 6-4.