SHENZHEN: Defending champion Agnieszka Radwanska reached the quarter-finals of the Shenzhen Open on Tuesday with a 6-0, 6-3 win over Sorana Cirstea.

The top-seeded Pole broke Cirstea six times, a day after being forced to save three match points in a lengthy three-set win over Chinese wild-card entry Duan Ying-ying.

Radwanska will next face Alison Riske of the United States, the player she beat in last year's final. Riske advanced by beating Tsvetlana Pironkova on Bulgaria 6-1, 6-1.

Third-seeded Johanna Konta also reached the quarterfinals after rallying to beat Vania King 1-6, 6-3, 6-2, while Wang Qiang defeated seventh-seeded Monica Niculescu 7-6 (1), 6-4.