British number one Kyle Edmund was knocked out of the Madrid Open quarter-finals by Canadian Denis Shapovalov.
The world number 22 lost 5-7 7-6 (8-6) 6-4 against the 19-year-old Canadian.
Edmund, 23, saved a match point in the second set but Shapovalov came through the decider on the Madrid clay after clinching an early break of serve.
Briton Edmund was appearing in his first Masters 1,000 quarter-final and will break into the world's top 20 for the first time on Monday.
Shapovalov, ranked 43rd, is regarded as one of the best young players in the world and hit 29 winners to Edmund's 19 in a tight match.
Edmund broke serve in the first game of the opening set but Shapovalov levelled and crucially broke serve again when 6-5 in front as Edmund failed to serve to stay in the set.
Edmund was involved in a heated exchange with the umpire late in the second set when he seemed to stop when a spectator shouted out during Shapovalov's service motion, but the Canadian's ace was allowed to stand.
Serving to stay in the match at 6-5 down in the following game, Edmund started with two double faults but held serve after saving a match point, and took the set on a tie-break moments later.
The decider was another tight set but Shapovalov's break of serve in the third game proved crucial.
Despite the defeat Edmund, who reached the Australian Open final earlier this year, will still continue his climb up the rankings after beating world number 10 David Goffin and 12-time Grand Slam champions Novak Djokovic in the earlier rounds.
Shapovalov will play Alexander Zverev in the semi-final after the German beat John Isner 6-4 7-5.
Dominic Thiem will play Kevin Anderson in the other semi-final after the Austrian ended world number one Rafael Nadal's 21-game wining streak on clay.