Dan Evans' bid to become the British number one ended when he lost in straight sets to John Isner in the second round of the China Open.
Evans could not break the American's serve and was beaten 7-6 (7-3) 7-5.
The 29-year-old, the world number 48, would have overtaken compatriot Kyle Edmund if he had reached the last four.
Evans' defeat leaves Andy Murray, who faces top-seed Dominic Thiem of Austria in the last eight on Friday, as the sole remaining Briton in the field.
Evans earned two break points in the ninth game of the first set but could not take either and big-serving Isner, 34, took the tie-break 7-3.
The second set looked to be heading for a tie-break too, until Isner found some magic to secure the only break of serve in the match and book a quarter-final spot against Stefanos Tsitsipas.
The Greek player beat defending champion Nikoloz Basilashvili of Georgia 4-6 6-3 6-2.