British number three Cameron Norrie lost 7-5 7-6 (7-4) to Canadian world number 19 Milos Raonic in the second round of the European Open in Antwerp.
The second set was even closer, but Raonic edged the tie-break to progress.
The fifth seed will face Bulgarian Grigor Dimitrov in the quarter-finals.
Norrie went on to another defeat in the doubles, partnering fellow Briton Dan Evans in a 7-5 6-3 quarter-final loss to fifth-seeded Belgian duo Sander Gille and Joran Vliegen.
Evans, who beat American Frances Tiafoe on Wednesday, will face Russian Karen Khachanov in the singles quarter-finals after the third seed fought back to defeat Belgian wildcard Zizou Bergs 5-7 6-4 6-4.