The 2008 champion, seeded 14, made no fewer than 77 unforced errors and served 11 double faults as she crashed 7-6 (7-4), 3-6, 6-4 to fellow Russian Maria Kirilenko.
“It’s a bad day and you have to get on with your life,” Sharapova said. “There are many worse situations in life. A bad day’s not going to stop me from doing what I love. I’m still going to go back on the court and work hard and perform. I’ll be back here on a Saturday of the second week, so you’ll watch.”
There was no such worry for another former world No1, Justine Henin, however, who powered past Kirsten Flipkens 6-4, 6-3 in her first Grand Slam match since coming out of retirement.
Henin now faces fifth seed Elena Dementieva in the tie of the second round after the Russian beat compatriot Vera Dushevina 6-2, 6-1.
Second seed Dinara Safina, US Open champion Kim Clijsters and Svetlana Kuznetsova are also through.
Men’s champion Rafael Nadal admitted he wasn’t at his best despite opened the defence of his title with a 7-6 (7-0), 6-1, 6-4 win over Peter Luczak.
The world No2 struggled to find his usual rhythm as he seeks a first tournament win since April.
“I was probably playing a little short of my best and he was playing well,” the Spaniard said. “You know always that you will be more nervous in the first round. First rounds are always difficult to play very well.”
Meanwhile, US Open champion Juan Martin del Potro was made to fight for his 6-4, 6-4, 3-6, 6-2 victory over Michael Russell, while Andy Roddick beat Thiemo de Bakker 6-1, 6-4, 6-4.