Maria Sharapova rolled over fellow Russian Nadia Petrova 6-1, 6-2 in the second round of the 700,000 dollar Bank of the West Classic on Wednesday.
Former world number one Sharapova needed just over an hour to beat current world number 10 Petrova.
Sharapova now has 13 wins and four losses in 2009 as she continued her domination over Petrova, winning seven of their eight career matches.
"I knew what I had to improve upon," Sharapova said. "I started that first match lousy. This time the goal was to get a better start."
Sharapova was playing just her 17th match since returning from a nine-month layoff because of shoulder surgery.
"I was aggressive the whole way through," she said. "I didn't have many letdowns and even when I made unforced errors I stayed with it."
In other second round matches, third-seeded and fourth-ranked
Elena Dementieva beat Maria Kirilenko, 6-1, 6-2 and Daniela Hantuchova upset seventh-seeded Agnieszka Radwanska 4-6, 7-6 (8/6), 6-1 in a two hour, 30 minutes match.
Samantha Stosur downed Monica Niculescu, 6-1, 7-5 in earlier second round action.
Anne Keothavong, of Britain, suffered a season-ending knee injury on Tuesday when she slammed into a fence while playing doubles.