Venus Williams' return to tennis came to an abrupt end in the last 16 of the ATP/WTA DC Open on Thursday, with the veteran American losing to Poland's Magdalena Frech in straight sets.
The 45-year-old seven-time Grand Slam singles champion, playing this week for the first time in 16 months, had become the oldest woman to win a WTA match in more than two decades with Tuesday's first round win over Peyton Stearns.
But Williams found the going harder against fifth seed Frech in Thursday's third round clash, losing 6-2, 6-2 in 1hr 13min.
Williams said she was nonetheless satisfied with her return to competitive tennis.
"I had so much fun," Williams said. "Not the result I wanted (but) I got to play a lot of matches, definitely a plus. I couldn't be happier...
"I ran out of gas today unfortunately...Sorry to have fell short. But I know I can play better and I know I will play better," added Williams, who is due to play in next month's Cincinnati Open after being handed a wild card into the event.
Frech will face third seed Elena Rybakina in Friday's quarterfinals.
Frech seized the early initiative with a dominant first set performance, breaking Williams in the fifth game to take a 3-2 lead.
The Pole duly held for a 4-2 lead and then broke again when Williams' serve unraveled in the seventh game.
The American double-faulted twice in quick succession to hand Frech three break points, and she converted the first to go 5-2 up, before holding to close out the set.
Williams was soon in trouble in the second set, blasting a routine smash well beyond the baseline to give Frech two break points in the first game.
PEGULA STUNNED
Frech pounced on that chance to grab the break for a 1-0 lead and then held for 2-0.
Williams held for 2-1 but was unable to threaten on Frech's serve in the fourth game as the world number 24 took a 3-1 lead.
Frech's shot variation continued to cause Williams problems in the next game and two wild long forehands from the veteran saw her surrender another break to go 4-1 down.
With the game slipping away, Williams loosened up and began to find her range to break back for 4-2.
The rally was fleeting as Frech broke again in the seventh for a 5-2 lead and then held to seal victory.
In other games on Thursday, Canada's Leylah Fernandez, the 2021 US Open finalist, upset top seed Jessica Pegula 6-3, 1-6, 7-5 to move into a quarterfinal meeting with Taylor Townsend on Friday.
Townsend took down sixth seed Sofia Kenin 6-3, 6-0.
Britain's Emma Raducanu continued her impressive run of recent form with a 6-4, 6-2 defeat of Japan's Naomi Osaka and will face Greece's Maria Sakkari on Friday.
In the men's draw, fourth seed Ben Shelton moved into the quarterfinals after beating Canadian 15th seed Gabriel Diallo 6-3, 6-2. Shelton will face compatriot Frances Tiafoe in the last eight, the sixth seed defeating ninth-seeded Italian Flavio Cobolli 6-1, 6-4.
Australia's Alex de Minaur is also into the quarterfinals after downing Jiri Lehecka 7-6 (7/4), 6-7 (6/8), 6-4.
Top seed Taylor Fritz also sailed into the last eight with a 6-3, 6-4 win over Matteo Arnaldi.