Birmingham: China`s Peng Shuai ended British hopes at the Birmingham WTA grasscourt tournament with a 7-6 (7/1), 6-1 win over teenager Heather Watson.
It was an impressive finish from third seed Peng, who had been pushed to the brink by another Briton, Naomi Broady.
"I played a really bad tie-break and after that my confidence went down," said Watson, who made her Top 100 debut on the rankings this week at No.93.
"I tried to forget about it and just started fresh in the second set but my returns let me down. I feel like I am getting stronger mentally, though, and I am excited for next week (Watson has a Wimbledon wildcard)."
Second seed and former world number one Ana Ivanovic stepped up her quest for the title as she brushed aside Canada`s world number 45 Rebecca Marino 6-3, 6-2 in 59 minutes.
Next up for Ivanovic is Mirjana Lucic, whose 6-2, 7-6 (7/4) win over Andrea Hlavackova ensured her second quarter-final appearance in two months, having previously failed to reach the last eight since 1999.
"I just focused on my own serve, and on her second serve I stepped in and was aggressive," said Ivanovic, who has only dropped a total of six games in her two matches so far this week.
"I felt good out there. I just kept thinking positively and tried to perform the best I could."
Fourth seed Daniela Hantuchova beat 16th seed Alla Kudryavtseva of Russia 6-4, 6-2, and will face American Alison Riske in the quarter-finals after Riske surprised French eighth seed Aravane Rezai 5-7, 7-6 (8/6), 6-2.
In another upset, New Zealand`s world number 151 Marina Erakovic beat seventh seed Sara Errani 5-7, 6-4, 6-3 to set up a quarter-final showdown against Peng.
Magdalena Rybarikova ended the run of Russian qualifier Arina Rodionova -- who had beaten top seed Kaia Kanepi in the first round -- 6-7 (1/7), 6-0, 6-1.
She will face Germany`s Sabine Lisicki, a 7-6 (7/1), 6-4 winner over Tamira Paszek of Austria.