Wimbledon champion Marketa Vondrousova has suffered an injury scare less than a fortnight before her title defence is due to start.
The Czech slipped and fell when leading 5-3 in the first set of her second-round match against Anna Kalinskaya at the Berlin Open.
Vondrousova clutched her right hip and called for a medical time-out before retiring two games later, with the score at 5-5.
Wimbledon takes place from 1-14 July, with Vondrousova set to start her title defence on the second day
The 24-year-old became the first unseeded player to win the Wimbledon women’s singles title when she beat Ons Jabeur in the final.
Russia’s Kalinskaya will face either world number three Aryna Sabalenka or compatriot Daria Kasatkina in the quarter-finals.
Elsewhere on Thursday, third seed Elena Rybakina reached the quarter-finals with a 6-4 7-5 victory over Veronika Kudermetova.
Kazakhstan’s Rybakina, the 2022 Wimbledon champion, will play former world number one Victoria Azarenka next.
Eight of the world’s top 10 are competing in Berlin, with only top-ranked Iga Swiatek and world number seven Jasmine Paolini absent.
