Defending champion Serena Williams gave herself a chance to make it two Cincinnati titles in a row.
She beat 14th-seeded Elina Svitolina, 6-4, 6-3, in the semifinals of the Western & Southern Open on Saturday.
Williams will face third-seeded Simona Halep, who beat Jelena Jankovic, 6-1, 6-2, in the other semifinal.
Halep's win will move her ahead of Maria Sharapova, who withdrew from Cincinnati because of a leg injury, into the No. 2 seed for the U.S. Open.