Matters appears positive as Sharapova raced to a 4-0 third set lead before winning 6-2 in the final set to end the three hour match.

Sharapova was playing in her first tournament since Wimbledon and turned in a less than stellar serving performance, hitting 17 doublefaults. Following the match she revealed the shoulder had been an issue earlier in the year.

"Bad news, because I'm withdrawing," Sharapova said. "It was pretty obvious out there. Coming into this tournament, I wasn't quite sure if I was going to be able to compete. Tomorrow I will go for an MRI."

"It's tough to go on court and not be close to even 50 percent. I'm too good of a player to go out there and try to fight through something that I think can eventually become something serious."

The injury puts Sharapova's participation in the upcoming Olympics in question as she seeks to lose the nagging injury which has reoccurred off and on in recent years.

Sharapova turned professional in 2001 and only three years later at age 17 won Wimbledon in 2004. In 2006 she took the title at the US Open and won her third grand slam this January at the Australian Open playing some of her best tennis ever.

More recently however Sharapova suffered a fourth round upset at the French Open to fellow Russian and hard hitter Dinara Safina and lost yet earlier at Wimbledon to Alla Kudryavtseva also of Russia in the second round.

With her mix of glamorous looks and powerful tennis game, Sharapova earlier this month was named by Forbes as the world's highest paid female athlete.