Reigning US Open champion Samantha Stosur said she was the latest victim of the grand slam winners\' curse after her stunning first-round exit from the Australian Open yesterday. Sixth seed Stosur was bundled out of the Open in straight sets by Romania\'s Sorana Cirstea in the biggest upset of the tournament so far. Cirstea took advantage of a host of unforced errors from the Australian to win 7-6 (7/2), 6-3 on her fourth match point and continue Stosur\'s miserable run in Melbourne. The 27-year-old Stosur has admitted she struggles with the expectations of local fans after losing in the second round in Brisbane and in the first round in Sydney this month. At a loss She noted that she had followed French Open champion Li Na and Wimbledon winner Petra Kvitova in winning her first major, but then losing her very next grand slam match — but she was at a loss to explain why. \"We all saw what happened last year [with Li and Kvitova] and now I\'ve kind of gone through that same trend,\" she said. \"I don\'t know why. Part of it is just that heightened expectation of wanting to do well, all that kind of thing. \"At least for the other girls, it was tournaments straight after. I struggled the couple of weeks after the US Open and then finished well at the [WTA] Championships, had a month off, then trained for a month. \"I don\'t know,\" she added. \"Maybe it\'s a little bit different. I don\'t know why it seems to be happening more often than not right now. \"I\'m sure if we could all change the way we\'ve responded straight after winning a grand slam, we would have.\" Stosur made far too many unforced errors against Cirstea, most of them coming off her favoured forehand side. Powerful strokes Cirstea, the world number 59, was content to keep the ball deep in the court with her powerful ground strokes and wait for mistakes from the Australian\'s racquet. \"I\'m obviously extremely disappointed... not just this tournament but the whole summer,\" Stosur said. \"There\'s not any other word for it but a total disappointment.\" \"I think it was one of those matches where I wasn\'t taking charge,\" she added. \"She hung in there and kept going for it and eventually got better and better.\"