British number two Heather Watson was unable to finish her first-round match at the Wuhan Open after complaining of dizziness.
The 24-year-old, who played two qualifiers on Saturday, had to retire from her clash against Madison Brengle while she was trailing 3-6 1-2.
After the first set, the doctor was called on court to check Watson's blood pressure after she suffered double vision, but she managed to carry on for three games before retiring from the match.
The Brit was competing for the first time since losing in the first round of the US Open.
