LONDON (AFP) - Maria Sharapova turned her grunting up to full volume but the 2004 champion could not find the game she needed to avoid becoming the first major casualty at this year's Wimbledon on Wednesday. As Novak Djokovic was easing into the third round in the men's draw, Sharapova went down to a three-sets defeat to Gisela Dulko in front of a sun-soaked centre court crowd that rallied behind the Argentinian underdog as her increasingly frustrated opponent's decibel levels rose. The Russian insisted she had been unaffected by the way a crowd that once adored her had turned against her. "That was the least of my worries today," she snapped after her 6-2, 3-6, 6-4 loss. "I was just trying to win a tennis match." Sharapova was playing only her fourth tournament since she resumed playing after a ten-month lay-off during which she underwent surgery on her right shoulder.But her exit was as much about how well Dulko played as any rustiness on the part of the Russian. Returning Sharapova's serve superbly and deftly moving her opponent around the court, Dulko fully deserved to race through the first set in just 35 minutes before opening up a 3-0 lead in the second. That proved to be the cue for a Sharapova comeback with the Russian reeling off seven games in a row. Few would have bet on Dulko at that stage but the 24-year-old steadied herself and, after a rollercoaster final set, she finally clinched the biggest win of her career on her fifth match point, triggering a standing ovation from the spectators. "It was tough," she admitted. "Maria is a great champion and she was competitive right to the end but the crowd was fantastic for me and I hope they will be there again for me in the next match." That will be against another Russian, the tenth seed Nadia Petrova, who sent Israel's Shahar Peer packing 6-3, 6-2. Zheng Jie, the 16th seed and a semi-finalist here last year, also went out, beaten 6-3, 7-5 by Slovakia's Daniela Hantuchova. Zheng made history last year when she became the first Chinese player to reach the last four of a Grand Slam tournament. But she arrived here in poor form after early exits from the French Open and grasscourt tournaments at Birmingham and Eastbourne and struggled to impose herself on Hantuchova, a former world number five. The Slovakian star will now face Japanese number one Ai Sugiyama, who had a 7-6 (7/5), 6-3 victory over Spanish qualifier Arantxa Parra Santonja. Djokovic eased into a third round meeting with big-hitting American Mardy Fish with a 7-5, 6-1, 6-4 win over German qualifier Simon Gruel, but the Serb was far from buoyant about his prospects for the rest of the tournament. "I can't say I am genuinely pleased because I had a lot of ups and downs in the match but I'm happy to get through in straight sets," he said. "I have no expectations, I'm not putting any pressure on myself, so I just try to go step by step. Mardy is a very difficult opponent on fast surfaces. I rate my chances 50-50."Former Australian Open finalist Jo-Wilfried Tsonga strolled into the last 32 without striking a ball after his second round opponent, Simone Bolelli of Italy, pulled out with a back injury. Tsonga, France's number one, will face either Croatian 22nd seed Ivo Karlovic or Steve Darcis of Belgium for a place in the last 16. Israel's Dudi Sela, who knocked Rainer Schuettler out of the Australian Open in the first round, repeated the trick with a 7-6, 6-3, 6-2 victory over the 18th seed, a semi-finalist here last year. Sela next faces 15th seed Tommy Robredo, who came back from two sets down to beat Stefan Koubek, of Austria.