All eight third-round matches had been scheduled for Thursday, but tournament officials decided to play only half of them when rains delayed the start of play until late in the afternoon.
Just two of the four matches that were finally put on the schedule were played to a conclusion.
Bouchard wound up advancing when third-seeded Samantha Stosur retired in the second set after losing the first one 6-2. Second-seeded Caroline Wozniacki reached the quarterfinals without having to take the court. Andrea Petkovic had to default the match with Wozniacki due to injury.
Jankovic will meet Bouchard and Voegele will face Wozniacki in the semifinals.
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