Italian Jasmine Paolini is into the Wimbledon quarter-finals after a tearful Madison Keys retired with an injury in the deciding set.
The American, 29, was forced to stop with the score locked at 6-3 6-7 (6-8) 5-5 on Court One.
Keys appeared to pick up the injury when serving for victory at 5-2 in the final set.
She took a medical timeout at the change of ends when leading 5-4 and was treated before leaving the court.
The 12th seed reappeared with strapping high on her thigh and was clearly hampered by the injury.
Paolini, 28, broke the serve of Keys again to level at 5-5 before Keys decided she could no longer continue.
“Right now I’m so sorry for her,” said Paolini. “To end the match like this is bad. What can I say?
“I think we played a really good match. It was tough. A lot of ups and downs. I’m feeling a bit happy but also sad for her. It’s not easy to win like that.”
French Open finalist Paolini had never won a match in the Wimbledon main draw before this year’s tournament.
After winning the first set, she trailed in the second 5-1 but rallied brilliantly to force a tie-break – which Keys eventually took on her fourth set point.
Keys established a big lead again in the decider before her injury.
Paolini will play the winner of the all-American meeting between Coco Gauff and Emma Navarro in the last eight.