The Dane won the match played mostly from the baseline against the Swiss veteran. Wozniacki improved her career record to 4-1 against the 52nd-ranked Schnyder.
The second-ranked Wozniacki will face Flavia Pennetta, who defeated Russian Alisa Kleybanova 6-3, 6-3.
Story continues below ↓advertisement | your ad hereSeventh-seeded Agnieszka Radwanska of Poland defeated Vania King of the United States 6-0, 6-3.
Dinara Safina, the 2008 winner in Montreal, won an all-Russian match against Nadia Petrova 7-5, 4-6, 6-4. The former No. 1 is playing her fourth tournament since a lower back injury sidelined her in November.
Kimiko Date Krumm withdrew with a strained left quadriceps, allowing 17th-seeded Marion Bartoli of France to advance. Bartoli will play Iveta Benesova on Thursday.
The Japanese veteran withdrew from the second-round match after reaching the main draw as the "lucky loser" from the qualifying tournament and defeating Monica Niculescu in the first round.
The 39-year-old Date Krumm returned in 2008 after a 12-year retirement, winning last year's Korea Open to become the second-oldest player after Billie Jean King to win an official event.
Wozniacki, a winner two weeks ago in her hometown of Copenhagen, passed Jelena Jankovic this week for the No. 2 spot in the rankings.
© 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.Guardiola fined for ref rantWozniacki advances to Danish Open quarters
