Dan Evans was knocked out of the China Open in straight sets by John Isner.
In a tight match in Beijing, Evans could not break the big American’s serve and lost 7-6 (7-3) 7-5.
The 29-year-old, ranked 48th in the world, would have overtaken Kyle Edmund as British number one if he had reached the semi-finals.
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 draw.
Evans fashioned two break points in the ninth game of the first set, but could not take either, and the 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 either Greece’s Stefanos Tsitsipas or Nikoloz Basilashvili of Georgia.