Johanna Konta missed out on a place in the quarter-finals at the AEGON Open in Nottingham.
The British No.1 suffered a surprise 6-4, 7-5 defeat to China’s Zheng Saisai after two hours of tough tennis on centre court.
Konta produced a determined display but seemed to be troubled by a back injury throughout the hard-fought match.
The 25-year old, who was seeded second for the tournament, hit four double faults and won just 38 per cent of points on her second serve.
Zheng, 22, is ranked at 62, 44 places below Konta. Konta moved up the world rankings to No.18 earlier this week.
This defeat came just a few days after Konta became the first British woman since Jo Durie in 1983 to break into the top 20 in the world.
Earlier in the week Konta enjoyed a comfortable first round straight sets victory ahgainst American Victoria Duval.