After defeating Serena Williams in the opening round of the Cincinnati Open, British number one Emma Raducanu put a damper on the American legend's farewell tour.
Williams, 40, lost 6-4, 6-0 in what was to be the farewell match of her career. Williams wants to retire after the US Open, which begins on August 29.
The 23-time Grand Slam winner lacked focus, and her 19-year-old rival punished her with a cool performance.
In the second round, Victoria Azarenka will face defending US Open winner Raducanu.
"I'm so grateful for the experience to have been able to play Serena and for our careers to have crossed over," said world number 13 Raducanu, who played superbly with her defence of the Grand Slam title in New York looming.
"Everything she has achieved has been so inspirational and it was a true honour to share the court with her."
