Sam Stosur of Australia defeated Agnieszka Radwanska of Poland 6-2, 5-7, 6-2 to reach the final of the Rogers Cup on Saturday.
Stosur broke Radwanska three times in the first set, but the Pole rallied to take the second when Stosur double-faulted. The Australian broke Radwanska to go up 5-2 in the third, then won the match with an ace.
The loss snapped a nine-match winning streak for Radwanska, who claimed her fifth WTA title last week in Carlsbad, California.
The 11th-ranked Stosur will face either Serena Williams or Victoria Azarenka, who will play in the evening semifinal.