BIRMINGHAM, England (AP) Petra Kvitova, the two times Wimbledon champion, suffered a blow to her bid for a third title when she joined a list of well-known names who have been beaten amidst the rainstorms at the Aegon Classic.

Kvitova is fighting back from form, fitness, and personal problems, and had been hoping for a good build-up here to the grass court Grand Slam, but lost 6-4, 4-6, 6-3 to Jelena Ostapenko, the promising world number 38 from Latvia.

The fifth-seeded Czech was disappointed not only to lose as early as the second round on her favourite surface, but to have done so after letting slip a break of serve and a 2-0 lead in the final set, when it seemed she had turned the match round.

Kvitova sometimes struggled with her movement in damp conditions and delivered two indifferent service games to allow Ostapenko, who often played better on the bigger points, to snatch the final set initiative back.

''It was difficult to put the pressure on her,'' said Kvitova, who played with her right thigh strapped. ''When she dropped serve (early in the final set) she became more dangerous.''

The 19-year-old repeated her win over Kvitova on hard courts in Doha in the first week of the year and now plays Madison Keys, the top 20 American, for a place in the semi-finals.

Play was halted by rain three times during the day, which was not only disruptive but made playing conditions difficult, and may also have contributed to the exit of former world number one Caroline Wozniacki, who was beaten 6-4, 6-7(5-7), 6-2 by Yanina Wickmayer, ranked at 49 but a former finalist here.

The repeated rain interspersed with thunderstorms may also have contributed to the exits earlier in the week of Agnieszka Radwanska, the top seed, and Belinda Bencic, the youngest player in the world's top ten.