Britain's Emma Raducanu struggled physically in a three-set loss to world number 219 Zhu Lin in the first round of the Ningbo Open in China.
Raducanu, 22, faded badly against the Chinese wildcard, losing 3-6 6-4 6-1 in two hours 26 minutes.
She had her blood pressure and vital signs taken during the second set and was given something to eat and drink by the physio.
She also had a medical timeout in the third set for treatment on her back, with her movement and service motion visibly hindered from then on.
World number 29 Raducanu retired with illness from the first round of the Wuhan Open last week.