Wozniak, a former world No. 21, was competing in her first tournament after an 11-month layoff.
The 27-year-old from Blainville, Que., hadn’t played since undergoing surgery on her right shoulder in September.
Krajicek will now face Toronto native Sharon Fichman in the semifinals. Fichman downed Britain’s Emily Webley-Smith 6-2, 6-3 on Friday to advance.
In men’s action, Vancouver’s Filip Peliwo advanced to the semis with a 7-6 (4), 6-4 victory over Bulgaria’s Dimitar Kutrovsky. Peliwo will face South Africa’s Fritz Wolmarans on Saturday.