ISTANBUL: Urszula Radwanska of Poland beat the last surviving seed in the Istanbul Cup quarterfinals when she outlasted No. 8 Tsvetana Pironkova of Bulgaria 6-2, 3-6, 7-6 (5) on Friday.

In reaching the semis, Radwanska earned her best result on tour in three years. She was bothered by right shoulder and right leg injuries over the last two years. The younger sister of top-10 player Agnieszka Radwanska, Urszula was still searching for her first WTA singles title. She won the doubles here eight years ago with Agnieszka.

She took more than two hours to beat Pironkova in a match with 17 service breaks.

Lesia Tsurenko endured a similar struggle to overcome fellow Ukrainian Kateryna Bondarenko 7-6 (13), 7-5 for the first time in three meetings. There were 13 service breaks in the 2 1/2-hour match.

This is only the second tournament this year in which Tsurenko has excelled. She came out of qualifying to reach the quarterfinals at Indian Wells in March, beating two top-10 players.

Errani in semis

In Bad Gasterin, Austria, top-seeded Sara Errani overcame neck problems to beat Russian qualifier Daria Kasatkina 6-3, 3-6, 6-2 Friday in the quarterfinals of the Gastein Ladies.

The 19th-ranked Italian received medical treatment while leading 4-3 in the opening set. She lost grip on her 151st-ranked opponent in the second set but dominated the third after two early breaks.

Errani, who reached the final in Bucharest last week, will next play the third-seeded Karin Knapp of Italy or Polona Hercog of Slovenia.

Earlier, Samantha Stosur advanced to her second semifinal of the season by beating Danka Kovinic of Montenegro 6-3, 6-2.

The second-seeded Australian, who won her seventh career title in Strasbourg in May, avoided break points to set up a semifinal match against Anna Karolina Schmiedlova of Slovakia.

A week after winning in Bucharest, the seventh-seeded Schmiedlova kept her winning run going by defeating Annika Beck of Germany 6-2, 6-3.

In a second-round match moved from Thursday because of thunder, Knapp beat Johanna Larsson of Sweden 6-3, 6-3.