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.