The 43-year-old tennis icon was no match for her 26-year-old opponent, who was born just weeks before Williams played her first Grand Slam final at the US Open in 1997
Venus Williams insists she's not ready to call time on her career, claiming on Saturday she is probably the only player able to keep competing until she's 50.
Five-time Wimbledon singles champion Venus Williams has been awarded a wild card for next month's championships.
Two-time Australian Open champion Naomi Osaka became the latest star to pull out of the opening Grand Slam of the year Sunday, leaving the tournament deprived of some of the biggest names in the game.
The U.S. Open turned over Arthur Ashe Stadium to the Williams sisters on Thursday for a prime-time first round doubles match that could have been Serena's last after the pair fell 7-6 (5), 6-4 to the Czech duo of Lucie Hradecka and Linda Noskova.
American 15-year-old Cori Gauff stole the show on the opening day of Wimbledon with a debut victory over five-time champion and her inspiration Venus Williams.
Serena Williams made her long-awaited comeback to tennis but the 23-time Grand Slam title winner and former world number one suffers defeat, playing alongside big sister Venus in a Fed Cup dead rubber.
Sloane Stephens stun two-times U.S. Open winner Venus Williams to ensure a new grand slam champion is crowned at the Flushing Meadows while Madison Keys hammer CoCo Vandeweghe to set up an all-American final.
Venus Williams vows to make amends for her Wimbledon final heartache by ending a bittersweet year on a high at the US Open.
Serena and Venus Williams close in on a fifth all-sister Wimbledon final while beaten quarter-finalist Dominika Cibulkova prepares to rush back to Slovakia to get ready for her wedding.
Dominika Cibulkova could be forced to postpone her wedding after a shock Wimbledon win over world number three Agnieszka Radwanska, while Serena and Venus Williams march into the quarter-finals.
World number 1 and Wimbledon defending champion Novak Djokovic goes perilously close to exiting the tournament at the earliest stage since 2008 before rain intervenes.
Serena Williams defeats her sister Venus at the US Open to move within two victories of her first calendar Grand Slam.