British number two Kyle Edmund is out of the Millennium Estoril Open after losing to qualifier Joao Domingues.
Domingues, the world number 242, fought back from 5-2 down in the third set and saved two match points before eventually beating the 22-year-old seventh seed 6-4 3-6 7-6 (7-2).
The victory is the 23-year-old's first on the ATP World Tour.
Elsewhere, Britain's Aljaz Bedene beat Hungary's Marton Fucsovics in the first round of the Istanbul Open.
The 27-year-old won 7-6 (7-3) 4-6 6-4, just two days after losing to Lucas Pouille in the Hungarian Open final.