Temperatures topped the 100-degree Fahrenheit mark Tuesday afternoon and even the late matches were played in 99-degree heat. Temperatures Wednesday are predicted to approach 100 degrees before easing to about 90 the rest of the week.
Pervak had dropped behind Julia Cohen 4-6, 6-3, 2-3 and the match had reached the 3-hour mark when Pervak said she couldn't continue because of heat-related illness.
No. 2-seeded Alexandra Panova survived a tight match that, while two sets, still lasted 2 hours, 14 minutes. Panova edged Sacha Jones 7-5, 7-6 (9-7). She fought off 5-of-6 break points in each set.
Fifth-seeded Bojana Jovanovski defeated Lesia Tsurenko 6-3, 2-6, 6-3 and No. 6-seeded Nina Bratchikova had five breaks in a 6-2, 6-4 win over Patricia Mayr-Achleitner. But Olga Puchkova ousted seventh-seeded Akgul Amanmuradova 6-3, 7-6 (14-12) and Magdalena Rybarikova routed Eva Birnerova, the No. 8 seed, 6-1, 6-1.
Also Tuesday, Marta Domachowska topped Carolina Garcia 1-6, 7-5, 6-0; Estrella Cabeza Candela was a 6-1, 6-1 winner over Ekaterine Gorgodze; Sandra Zaniewska defeated Elina Svitolina 6-1, 7-6 (7-4) and Alberta Britani beat Zarina Diyas 6-3, 6-1.
Laura Pous-Tio advanced when, after she went up 6-1 2-0, Noppawan Lertcheewakarn retired with an elbow injury.