Reigning US Open champion Samantha Stosur crashed out in the first round of the Australian Open on Tuesday but second seed Petra Kvitova and Maria Sharapova both eased through. In the first major shock at the season-opening grand slam, local favourite Stosur delivered an error-strewn performance in the Rod Laver Arena to lose 6-7 (2/7), 3-6 to Romania's Sorana Cirstea. It continued a miserable run in Melbourne for the 27-year-old sixth seed, who has failed to make it past the fourth round in 12 attempts but came into this year's tournament as a grand slam champion after victory in New York. Stosur, who this month suffered early exits in Brisbane and Sydney, has admitted she struggles with the expectations of local fans and a succession of unforced errors, most off her usually favoured forehand, cost her dear. Cirstea, the world number 59, won the first set tiebreak easily and after early trades of service breaks in the second set, secured a vital break in the fifth game, then held her nerve to move into a 5-3 lead. Stosur's normally reliable serve cracked as Cirstea brought up her first two match points at 15-40. The Australian saved both but could not close out the game, and Cirstea eventually clinched victory when a Stosur forehand sailed long -- her 33rd unforced error of the match. "There's not any other word for it but a total disappointment," Stosur said. "It's not through lack of trying or not wanting it or anything like that. I mean, you can't pick the times that you want to play well," she added. "Probably the whole of Australia hates me right now," Cirstea said. Earlier, Wimbledon champion Kvitova and former world number one Sharapova both turned in impressive performances to crush their opponents. After going 2-0 down at the start of the match, Kvitova won 12 straight games to sweep aside Russia's Vera Dushevina in straight sets 6-2, 6-0. The Czech left-hander dropped her first service game but once she found her range there was nothing Dushevina could do to stop the onslaught. Kvitova, 21, who reached the quarter-finals in Melbourne last year, broke the Russian three times in each set and faced only two break points on her own serve, underlining her dominance. "After a slow beginning it was fine," Kvitova said. "You know, it looks easy, the score, but it wasn't. The games, some were very close and I'm glad that I'm through." Kvitova now goes on to play Carla Suarez Navarro after the Spaniard beat Romania's Irina-Camelia Begu 6-1, 7-5. Former champion Sharapova demolished Argentina's Gisela Dulko 6-0, 6-1 in less than an hour. Sharapova, who won the title in 2008, was at her ruthless best as she overpowered the Argentine in stifling conditions. The Russian fourth seed also showed no signs of a left ankle injury that forced her to withdraw from the Brisbane International two weeks ago. "I knew I had a tough opponent today," a delighted Sharapova said. "I focused on every point and took her time away -- she's a player who loves time on the ball." Sharapova has a relatively easy passage into the third round with her next opponent US qualifier Jamie Hampton. Seventh seed Vera Zvonareva beat Romania's Alexandra Dulgheru 7-6 (7/4), 6-7 (5/7), 6-3 while France's Marion Bartoli, the ninth seed, beat compatriot Virginie Razzano 7-5, 6-0. German 14th seed Sabine Lisicki survived a scare from Swiss qualifier Stefanie Voegele to win 6-2, 4-6, 6-4 and 17th seed Dominika Cibulkova thumped fellow Slovak Magdalena Rybarikova 6-3, 6-1. Two seeded Russians also progressed. Anastasia Pavlyuchenkova (15) downed Czech Klara Zakopalova 7-6 (7/5), 6-1 and Maria Kirilenko (27) beat Australia's Jarmila Gajdosova 6-4, 6-2.