Zheng Jie was forced to wait until Saturday to complete her Birmingham WTA grasscourt quarter-final against Roberta Vinci when rain halted the tie with the Chinese player 6-3, 5-6 ahead. Zheng, the world number 32, had served for the match at 5-4 in the second set. Only one match was completed on Friday as Misaki Doi of Japan wrapped up a 6-4, 7-5 win over Stephanie Foretz-Gacon in a third round tie suspended midway through the second set on Thursday. The 21-year-old Doi will play her first ever WTA Tour quarter-final against Jelena Jankovic, who is looking for her first title since 2010. Left-hander Doi clearly enjoys the grass -- she beat Bethanie Mattek-Sands and Zheng on her way to the third round of Wimbledon last year. Doi and Jankovic will be on Centre Court following the completion of the Vinci-Zheng match on what could be a very busy Saturday, featuring both the quarter-finals and semi-finals. The other quarter-finals feature Melanie Oudin and Irina Falconi in an all-American tussle, while Russia\'s Ekaterina Makarova faces Hsieh Su-Wei of Taiwan.