Melanie Oudin of the United States ousted 10th-seeded Sorana Cirstea of Romania 3-6, 6-3, 6-2 Tuesday at the Aegon Classic grass-court tournament.
Zheng Jie defeated Alla Kudryavtseva of Russia 6-4, 4-6, 6-3 in her opening match.
Zheng helped fuel Chinese tennis after becoming the country's first player to reach a Grand Slam semifinal in Wimbledon in 2008, where she made history two years by winning the first doubles title.
Although the 28-year-old Zheng hasn't fully recovered from a wrist surgery, she defeated the hard-hitting Russian. She is ranked No. 32.
"It's really good to be back on grass and I aim to be back in the top 20 again" Zheng said.
She will play against the No. 76th-ranked Anne Keothavong of Britain in the second round. Keothavong advanced after beating the 12-seeded Tamira Paszek of Austria 6-2, 7-5.
Eleventh-seeded Iveta Benesova of the Czech Republic lost her match 6-2, 6-1 to Tara Moore of Britain. Benesova called the grass was "not really playable" and "full of holes."
Timea Babos of Hungary and Elena Baltacha of Britain had their matches suspended when darkness halted play.
Babos, the No. 14 seed, was in a tight match 6-4, 4-6, 3-3 against Alison Riske, the American qualifier who reached the semifinals here two years ago.
Meanwhile Baltacha, the No. 15 seed, lost the first set 4-6 but was up 3-2 in the second against Chang Kai-Chen of Taiwan.