Watched by a raucous crowd, including her sister, Venus, in Flushing, New York, Williams, a 23-time Grand Slam champion and former world No. 1, lost 7-5, 6-7, 6-1 in an absorbing contest lasting more than three hours where she saved multiple match points.
She had briefly delayed her retirement with a shock win in the second round against World Number 2 Anett Kontaveit.
Williams announced she would be “evolving away” from tennis after the U.S. Open in a cover story for Vogue earlier this year.
This is a developing story. Check back for updates.