Kyle Edmund is out of the French Open after retiring during his second-round match against Uruguayan Pablo Cuevas because of a left knee injury.
The British number one, 24, trailed 7-6 (7-3) 6-3 2-1 when he called the trainer.
After a lengthy chat the 28th seed told Cuevas he could not continue and shook hands with his opponent.
Edmund's exit means Johanna Konta is the only Briton left in the singles at Roland Garros.
Edmund was bidding to reach the last 32 of the French Open for the third successive year, having ended a five-match losing streak on clay this year with a gutsy five-set win over France's Jeremy Chardy in the opening round.
But the Yorkshireman never looked comfortable from the start against 33-year-old Cuevas, a clay-court specialist who has won all of his six ATP Tour singles titles on the surface.
After losing his opening service game of the match, Edmund fought back to level the first set at 4-4 before Cuevas ran away with the tie-break.
Cuevas caused problems with his dominant backhand as Edmund struggled to unload his favoured forehand, the Briton winning just four points on his way to losing the final four games of the second set.
That left Edmund needing to do something he had never done in his career - win from two sets down.
From this position he had lost 13 previous matches and another exit followed when he shook hands with world number 47 Cuevas, who will face Austrian fourth seed Dominic Thiem in the last 32.