Cameron Norrie's hopes of qualifying for the upcoming ATP Finals suffered another blow as he lost in straight sets to Marcos Giron in the last-16 of the Erste Bank Open in Vienna.
The British number one lost 3-6 4-6 in one hour and 21 minutes to further damage his hopes of making it into the year-end tournament, having missed three chances to break the American's serve on the day.
Giron broke in the sixth game of the first set to move into a 4-2 lead, but Norrie broke back to love immediately before squandering the chance to level the contest.
The world number 13 racked up four unforced errors in the eighth game as he was broken for a second time, with Giron then comfortably seeing out the first set.
Norrie would get off to the perfect start in set two, with an ace clinching a love hold in the first game, but he missed his first break point in the sixth game as Giron held for 3-3.
Giron took advantage of that missed opportunity to clinch his own break before moving one game away from the match with a love hold, but Norrie would force the world number 58 to serve it out following back-to-back aces.
Norrie had two chances to break in the 10th game at 40-15 up, but he wasted both of them as Giron won four points in a row to seal his place in the quarter-finals against Grigor Dimitrov.
GB are still represented in the singles competition in Vienna by Dan Evans, who will tackle Denis Shapovalov of Canada in his quarter-final match on Friday.