Poland Open: Siegemund upsets fourth seed Lin to reach last eight

German Laura Siegemund advanced to the quarter-finals of the Poland Open by winning against Chinese Lin Zhu, the No 4 seed, 6-4, 6-4 at the Legia Tennis Centre in Warsaw on Thursday.

Siegemund, ranked No 153, will face Italian Lucrezia Stefanini next.

The 35-year-old German beat Pole wildcard Maja Chwalinska (6-4, 6-1) ahead of her victory.

In the previous round of the Warsaw tournament, Zhu, ranked No 38, defeated Xiyu Wang (6-4, 6-2).

Warsaw WTA 250, other last 16 results (Legia Tennis Centre, clay, USD 259.303, most recent results first):

• Iga Swiatek vs. Claire Liu
• Rebecca Sramkova vs. Karolina Muchova: thursday
• Linda Noskova (8) beat Viktoria Hruncakova: 6-3, 6-3
• Lucrezia Stefanini beat Jodie Burrage: 6-4, 6-1
• Heather Watson beat Yuliya Hatouka (Q): 6-2, 5-7, 6-1
• Tatjana Maria beat Clara Tauson: 6-4, 6-0
• Yanina Wickmayer beat Tereza Martincova: 6-2, 6-2