Sharapova makes a backhand return to Petkovic (Photo: AP)
Andrea Petkovic reached the quarter-finals of a Grand Slam for the first time with the comprehensive win, celebrating with her now famous jig - the Petkodance - first unveiled on her way to the fourth round of the 2010 US Open.
Petkovic, a political science student who plays the drums and reads Goethe and Oscar Wilde in her spare time, was never in trouble against a misfiring Sharapova.
She reached the fourth round when Venus Williams pulled out injured after just seven points, but looked right at home on the big stage against the experienced Russian.
Petkovic has made up for her first outing at Melbourne Park when in 2008, the same year Sharapova won the title, she injured her knee in the first round against Anna Chakvetadze and was out injured for eight months.
Sharapova was disappointing against Petkovic, serving five double faults and making 30 unforced errors to her opponent's nine.
She has struggled since she returned to the tour in 2008 following shoulder surgery and looks a shadow of the player who won three Grand Slam titles.