DOHA, Qatar — Andrea Petkovic of Germany eliminated fourth-seeded Garbine Muguruza 6-1, 5-7, 6-2 to reach the Qatar Open semifinals on Thursday.
Petkovic, a former top-10 player who has dropped to 29th, met Muguruza with a 2-0 record against the Spaniard, but both wins were before 2014, since when Muguruza has risen to a career-high ranking of No. 5.
Petkovic will next face Jelena Ostapenko of Latvia, who followed up her win over two-time Wimbledon champion Petra Kvitova by defeating Zheng Saisai of China 6-4, 6-3.
Zheng knocked out Australian Open champion Angelique Kerber in the second round but struggled to match the same high standard.