Two-time runner-up Ons Jabeur retired from her first-round match against Viktoriya Tomova when trailing by a set and a break after struggling physically on a hot day at Wimbledon.
The Tunisian former world number two, who has dropped down the rankings over the past year because of injuries and is now 59th, left the court for 14 minutes at 3-2 in the first set when she took a medical timeout.
She had looked distressed before that while sitting on her chair at the changeover, burying her head in her towel, drinking water and putting an ice towel around her neck before a physio took her blood pressure.
She returned to the court but never looked comfortable as the temperature at Wimbledon headed towards 30C and called it a day with Bulgaria’s Tomova leading 7-6 (7-5) 2-0.
The weather forecast points to temperatures climbing as high as 33C in south-west London on Monday.
The hottest opening Wimbledon day on record was in 2001, when temperatures reached 29.3C. The hottest-ever day at SW19 was 1 July 2015, when it reached 35.7C.