The top seeded Williams eliminated Italy’s Schiavone 6-3, 6-2 in the WTA Tour’s $2.4 million hardcourt tournament.
“She’s a grand slam champion so I had to really focus,” said Williams, who was the runner-up in Toronto in 2000.
“I made a few errors but it’s my first match on hard (courts) in a really long time.” Williams next faces Kirsten Flipkens, who beat Dutch qualifier Kiki Bertens 7-5, 3-6, 6-2.
Flipkens ousted Venus Williams in the first round earlier this week, but this will be her first clash against Serena Williams.
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