Third seed Svetlana Kuznetsova beat Roberta Vinci 6-2 7-6 in Toronto to reach the Rogers Cup third round.
Kuznetsova is a former US Open champion
The Russian blasted through the first set in 29 minutes in her first match since the Wimbledon quarter-finals.
However, she needed an hour to prevail in a tense second set, saving a set point before finally clinching the match in a tie-break 9-7.
The tournament is part of 22-year-old Kuznetsova's build-up to the US Open, which she won in 2004.
She next plays either American Meghann Shaughnessy or Czech Lucie Safarova.