(CNN) -- Unseeded Russian Maria Sharapova produced her most impressive display since returning from shoulder surgery, crushing compatriort Nadia Petrova in straight sets in the second round of the Bank of the West Classic.
Sharapova was in imperious form as she cruised past compatriot Nadia Petrova in California.
Former world number one Sharapova needed just over an hour to beat fifth seed Petrova 6-1 6-2 at Stanford University, California.
"I was aggressive the whole way through," Sharapova told reporters. "I didn't have many letdowns and even when I made unforced errors I stayed with it."
Sharapova now has 13 wins and four defeats in 2009 as she continued her domination over Petrova -- winning seven of their eight matches.
In other matches, another Russian, third seed Elena Dementieva, defeated compatriot Maria Kirilenko 6-1 6-2.
Unseeded Czech Daniela Hantuchova maintained her impressive form with a 4-6 7-6 6-1 victory over seventh-seeded Agnieszka Radwanska, while Australian Samantha Stosur saw off Romanian Monica Niculescu 4-6 7-6 6-1.
In the men's Los Angeles Open, top seed Tommy Haas and eighth seed Marat Safin both cruised into the quarterfinals, where they will now face each other.
Haas, who reached the semifinals at Wimbledon, beat American wild card Jesse Levine 6-1 6-3 while Russian Safin toppled Latvian Ernests Gulbis 2-6 6-3 6-4.