China\'s Zheng Jie reached the quarter-finals of the Birmingham grasscourt tournament on Thursday, but admitted she almost missed the event after forgetting to enter. Zheng clinched a 6-4, 6-1 win over Andrea Hlavackova of the Czech Republic, having had to play the qualifying rounds last weekend despite her ranking of 32 trumping some main draw players who stand at 120 in the world. \"I had to enter six weeks before, and at the time I was practicing in China and forgot. I wanted to come here anyway though, even if it meant playing in the qualifying. Before Wimbledon it\'s only two weeks of grass court tournaments,\" said Zheng. Zheng, who became China\'s first Grand Slam semi-finalist at Wimbledon in 2008, once again showed her comfort on grass, winning eight of the last nine games against the big-hitting Hlavackova. \"I\'m so happy to be in the quarter-finals,\" said Zheng. \"I have played five singles matches already this week, and doubles also, so I\'m a little bit tired. \"Sometimes playing a lot of matches is good and sometimes it\'s not! But I\'m happy I made it through today and I just need to focus on the next match right now.\" Zheng will next face fourth-seeded Italian Roberta Vinci who dropped the middle set of her match against Britain\'s Heather Watson but rebounded to win 6-3, 4-6, 6-1. Vinci is fresh off her first Grand Slam title, winning the doubles at the French Open with Sara Errani. Zheng leads Vinci in their head-to-head series, 2-1, winning their last two matches in straight sets. Friday\'s quarter-final is their first career meeting on grass. Also moving on were fifth seed Jelena Jankovic, eighth seed Ekaterina Makarova, No.13 seed Hsieh Su-Wei, Irina Falconi and Melanie Oudin. Stephanie Foretz Gacon of France and Japan\'s Misaki Doi played in the last match of the day, with Doi leading 6-4, 2-2 when play was suspended due to rain.