Venus Williams' short but unexpected run at the Birmingham Classic came to an end with defeat by second seed Jelena Ostapenko in a three-set thriller.
The 43-year-old American fought tenaciously but lost 6-3 5-7 6-3 at the Wimbledon warm-up event.
"Venus is an idol for a lot of people, it was very special," said Ostapenko.
Williams will take positives from her performance and was handed a Wimbledon wildcard earlier this week.
"Venus is a great player and it's an honour to share a court with her, she's a really dangerous player on grass. It was hard but I managed it, I was fighting until the last point," said Ostapenko.
"It's great to play against players like Venus, she's a great champion - that hasn't gone anywhere, it will always be with her."
Williams battled well despite injury troubles, securing a hard-fought break in the fifth game, but the Latvian won four games in succession to take the opening set.
Williams' victory on Tuesday over Italy's Camila Giorgi was only her second singles win in almost two years after lengthy injury lay-offs.
As was the case against Giorgi, the five-time Wimbledon champion had to take a medical timeout - this time leaving the court four games into the second set.
The seven-time Grand Slam singles champion wore strapping on her right knee throughout and did not look to be moving well on her return to the court.
But she fought on and continued to make life difficult for Ostapenko, rescuing match point at 5-3 to force the 2018 Wimbledon semi-finalist to serve for the match.
An unshakeable Williams then gave the Birmingham crowd hope she could pull off a comeback when she broke Ostapenko's serve and won the next two games, securing the second set with a stunning break to 15.
Then, with the 2021 Eastbourne winner rattled - hitting double faults and making basic mistakes - Williams took an early third-set break.
But Ostapenko rallied, responding three games later with her own impressive break to love and winning the next two games to see the match out in almost two-and-a half hours.
Meanwhile, Russian fourth seed Anastasia Potapova survived a scare and completed a comeback of her own with a 3-6 6-2 7-6 (7-0) win over American Caty McNally to set up a quarter-final against Britain's Harriet Dart on Friday.
After rain led to play being suspended, Poland's Magdalena Frech beat Romanian Sorana Cirstea 6-3 6-7 (1-7) 6-4 in a gruelling match to set up a quarter-final against Ostapenko.
Former French Open champion Barbora Krejcikova edged out Czech compatriot Tereza Martincova 6-4 6-4 to set up a quarter-final against another countrywoman, 18-year-old Linda Fruhvirtova.