Denmark's Caroline Wozniacki will try to win her first title of 2017 after reaching her sixth final with victory over Sloane Stephens at the Rogers Cup.
Sixth seed Wozniacki, the champion in 2010, saw off unseeded American Stephens 6-2 6-3 in the first semi-final in Toronto.
Defending champion Simona Halep takes on Ukraine's Elena Svitolina in the second semi-final later on Saturday.
The pair will play twice in a day after rain disrupted the schedule.
Svitolina lost the first set against Wimbledon champion Garbine Muguruza before the rain arrived on Friday night, and the fifth seed fought back on Saturday to win 4-6 6-4 6-3.
Romanian second seed Halep swept past France's Caroline Garcia 6-4 6-2 in the last of the quarter-finals.