Maria Sharapova exited Wimbledon after losing her second-round match against Gisela Dulko, 6-2, 3-6, 6-4.

Dulko, of Argentina, needed five match points to seal victory against the 2004 champion and will play Nadia Petrova, the 10th seed from Russia, for a place in the quarter-finals.

Sharapova, who slipped down the rankings after spending ten months out of the game with a shoulder injury, endured a shaky start but looked to have got her game going when she strung together a sequence of seven consecutive games, and the decibel levels rose significantly as she grunted through points.

But Dulko finished the stronger despite missing four match points as she booked her place in the last 32. The Argentinian won just three games in her two previous meetings with Sharapova but matched that tally inside the first 12 minutes on Centre Court.

Dulko followed up a comfortable opening service game with a crashing forehand pass that gave her three break points. Sharapova saved two but put a forehand wide to fall 2-0 behind.

Dulko, who quickly found a rhythm with her dangerous forehand, was rarely troubled on her own serve and broke the mis-firing Russian for a second time in the eighth game.

Oozing confidence, Dulko broke her opponent again early in the second set to lead 6-2 and 3-0.

A first ace of the match helped Sharapova hold serve and the flow of the match began to turn when she broke the Argentinian for the first time in the next game.

A love service game brought the former champion level and she edged in front with Dulko came up with two double faults.

Dulko was suddenly in freefall and, although she saved two set points, Sharapova held her nerve to win her sixth straight game and take the second set 6-3 to force a decider.

Sharapova extended her winning sequence at the start of the third set but Dulko stopped the rot by holding serve in the second game.

There were signs of a return of the swinging forehand as Dulko broke her opponent to edge in front but just as quickly dropped her serve. As the tension grew, Sharapova received a time violation in her third service game of the deciding set and the match took another turn when the Russian was broken to love in the seventh game.

Dulko then served out for a memorable win she dubbed the best of her career. "It's a great day for me," Dulko said. "She's a great champion and it's the most important tournament in the world. I didn't play very well in the second set but I kept fighting and everything came good."