Lisicki, the 15th seed, won the contest 6-4, 6-3, in a shock result which saw the recent French Open champion bow out, leaving open her side of the draw and putting her number one rank at risk.
However, Sharapova wasn’t too worried about the number one ranking at this stage.
“What I achieved a few weeks ago doesn’t just go away in a few minutes,” Sharapova told reporters. “I’ll have that for the rest of my career.
“But the tennis world always keeps going. You have to raise your level at that point, even when your opponent plays really great tennis. Just today wasn’t my day. But as far as that motivation, of course you want to stay at the top as long as you can. Obviously everyone guns for that spot, as it is the top spot.”
Elsewhere on Monday, second seed Victoria Azarenka went through with a straight set victory over Serbian glamour 14th seed Ana Ivanovic, while Serena Williams did it tough in three sets to get past Yaroslava Shvedova. Third seed Agnieszka Radwanska also progressed.
On the men’s side of the draw there were no shocks, as Novak Djokovic knocked off compatriot Viktor Troicki in straight sets, while third seed Roger Federer got past Belgium’s Xavier Malisse in four sets.