Andy Murray lost to world number 240 Matteo Viola in the third round of the Rafa Nadal Open in Majorca.
The Briton was beaten 3-6 6-4 7-6 (7-3) in the Challenger Tour event after hitting a double fault on match point in the final-set tie-break.
The second set saw Murray, 32, lose his serve three times.
He struggled physically during the third set, receiving treatment on his left thigh during two medical time-outs which he said was for "cramping".
Murray added afterwards that he was "very tired" and said "physically, I need to get better".
Asked about his time at the event, he said: "Yeah, it was good, I enjoyed it. I would have liked to have played more matches but it was good, I played two competitive matches."
Wildcard Murray went 2-0 down at the start of the third set, and although he got straight back on serve, the 32-year-old Italian sealed victory in the deciding tie-break.
It was Murray's third tournament since returning to singles action following hip surgery in January.