British number three Kyle Edmund is out of the Nottingham Open after a 6-4 7-6 (7-5) defeat by Ukrainian world number 32 Alexandr Dolgopolov.
Edmund, 21, who is ranked at a career-best 68th after making the third round at Queen's, was edged out in a tight match that featured one break of serve.
British number four Dan Evans plays Lithuania's Ricardas Berankis later.
Second seed Pablo Cuevas or France's Stephane Robert are Evans' possible third-round opponents.