India's Sania Mirza stunned eighth seed Sybille Bammer 6-2, 5-7, 6-3 to reach the final of the Stanford Classic on Saturday.
The unseeded 20-year-old, whose only Tour title came in Hyderabad in 2005, outlasted the Austrian under the hot sun in two hours and 14 minutes.
Mirza will face top seed Anna Chakvetadze, who overcame third seed Daniela Hantuchova 6-7, 6-3, 6-2.
Mirza began the match crushing her huge forehand and powering her backhand crosscourt.
But in the second set, she began to play more conservatively and paid for it by being broken four times.
In the third set, Mirza broke Bammer to 4-3 when she ripped a forehand down the line and the Indian won the match when she hit a forehand crosscourt winner on her fourth match point.
Chakvetadze recorded her ninth straight victory in the United States after out-running Hantuchova, who troubled the Russian with some aggressive groundstrokes.
Chakvetadze has a 2-0 record against Mirza, including her semi-final victory in Cincinnati last week.