Myskina, the tournament's top seed, beat unseeded Martina Sucha of Slovakia, 6-4, 6-4, continuing the march toward her second straight final at this event. Last year, she was beaten by Katarina Srebotnik of Slovenia in the title match.
Fourth-seeded Sofia Arvidsson -- a native of Sweden and a big crowd favorite -- was leading Eva Birnerova of the Czech Republic, 4-6, 6-3, 2-0, when Birnerova retired from the match with an undisclosed injury.
In Saturday's semifinals, Myskina faces Arvidsson; and Jie plays Pironkova.
Sunday's title winner will earn $22,900.