Andy Murray suffered his second successive quarter-final defeat on Thursday as Borna Coric sent him crashing out of the Dubai Tennis Championships 6-1 6-3.
Third seed Murray had cruised through the opening two rounds of the tournament earlier this week, but he had no answer to the Croatian teenager, Coric winning in 79 minutes.
Coric took six successive games in the opening set, his athleticism around the court and impressive forehand causing significant problems for Murray.
The Scot steadied the ship in the second set but Coric - the world number 84 - got a crucial break in the sixth game before serving out for the match.
It is another failure in the last eight for Murray, who lost to Gilles Simon earlier this month at the World Tennis Tournament in Rotterdam, while Coric continues to add to his growing reputation on the ATP Tour.
The 18-year-old will face defending champion Roger Federer in the semi-finals, after the second seed was handed his last four place by Richard Gasquet's retirement.
Federer had dominated the opening set with three breaks of serve to take it 6-1, but Gasquet was unable to continue due to a back injury.
Novak Djokovic will meet Tomas Berdych in the other semi-final, the top seed cruising through 6-1 6-1 in 49 minutes against Marsel Ilhan.
Ilhan only managed 28 points in the match as his illustrious opponent dominated proceedings, Djokovic winning five consecutive games in the first set, and six in the second to secure victory.
Things were trickier for Berdych, who overcame Sergiy Stakhovsky 6-3 4-6 6-2, expending more energy than he would have wanted with a clash against the world number one on the horizon.