Sharapova will hope to challenge for the US Open title
Maria Sharapova continued her comeback from injury with victory over Jarmila Groth in round one of the LA Women's Tennis Championships in Los Angeles.
The 22-year-old Russian, who returned in May after nine months out because of shoulder surgery, won 6-0 6-4.
Sharapova will meet third seed Victoria Azarenka of Belarus in round two.
France's Marion Bartoli, who beat Venus Williams to win in Stanford on Sunday, has pulled out with a calf injury.
Sharapova was joined in the second round by 10th seed Flavia Pennetta of Italy, a 6-2 5-7 6-0 winner against American Varvara Lepchenko but the number 11 seed Virginie Razzano of France lost 7-6 (7-5) 6-3 to Russia's Anna Chakvetadze.
Three-time Grand Slam champion Sharapova completely outclassed Slovakia's Groth in the opening set but failed to find the same level of consistency in the second.
Breaks were exchanged before Groth erred on a forehand and then fought off three break points to hold a 4-3 lead.
But Sharapova then levelled, broke Groth to love and served out to win the match with a vicious forehand return down the line.
"Her game plan was to attack from every single angle she could," said Sharapova, who is still working to strengthen her serve following surgery in 2008 and lost in the quarter-finals of the Stanford Classic last week to Venus Williams.
"But she wasn't able to do that consistently because I was able to retrieve and make her hit more balls."
Lucie Safarova of the Czech Republic overcame 15th seed Kaia Kanepi of Estonia 6-3 7-6 (7-4) while American qualifier Jill Craybas was a 7-6 (9-7) 6-2 winner against Italian 16th seed Francesca Schiavone.
In qualifying for the tournament, British number two Elena Baltacha was beaten 4-6 6-4 7-5 in round one by American wildcard Lindsey Nelson, and British number four Melanie South lost 6-3 3-6 6-3 to 17-year-old American Melanie Oudin in round two.