Karolina Pliskova was thrashed in the opening round of the Qatar Open on Sunday as she slumped to a straight-sets loss against Margarita Gasparyan.
The Czech 10th seed produced a limp display in Doha as Gasparyan recorded a surprisingly straightforward 6-1 6-1 triumph.
Pliskova's service game fell to pieces, with six double faults underlining her woes, though Gasparyan ensured her beleaguered opponent was duly punished.
Zheng Saisai set up a last-16 clash with tournament favourite and Australian Open champion Angelique Kerber after defeating Varvara Lepchenko 6-2 7-6 (6-8).
A host of other leading contenders given byes learned the identity of their second-round rivals, with third seed Agniezska Radwanska to meet Kateryna Bondarenko, a 6-4 6-4 winner against Annika Beck.
Reigning champion Lucie Safarova will take on Cagla Buyukakcay after the world number 143 from Turkey overcame Lucie Hradecka 6-4 6-7 (5-7) 6-2.
Dona Vekic hammered Omani wildcard Fatma Al Nabhani 6-0 6-0, while Jelena Ostapenko beat Zarina Diyas 6-1 6-3, and Daria Kasatkina saw off Wang Qiang 6-1 2-6 6-3.
Elsewhere in the draw, Eugenie Bouchard won a third-set tie-break to oust Anastasija Sevastova, while Yulia Putintseva and Andrea Petkovic also progressed.