Laura Robson followed Olly Golding out of the Wimbledon juniors on a disappointing afternoon for the British youngsters on Court 12.
Hopes were high that 16-year-old Robson would repeat her feat of two years ago, when she was a shock winner of the girls' singles.
However she did not bring her best service game into the semi-final against Japanese 17-year-old Sachie Ishizu, and let two set points slip away in the second set as she lost 7-5 7-6 (7/5).
Robson made only 49% of her first serves, compared to her opponent's 69%, and that was key to the outcome.
The serve has become a weapon for Robson and even troubled Jelena Jankovic, the fourth seed, in the first round of the women's singles.
But today she only found two aces, and Ishizu capitalised.
Robson was broken in her first service game but immediately hit back and for a while the opening set stayed on serve.
Australia-born Robson crunched her racquet into the grass in frustration at one poor shot though and seemed to be struggling for control against the 10th seed.
A solid love service game seemed to perk her up though, and she moved to 15-40 on the Ishizu serve before establishing a break with a fine two-handed backhand service return down the line.
Serving for the set at 5-4, Robson gave up a break point at 30-40 when she fired a forehand over the baseline, and then another after getting back to deuce, and on the second occasion Ishizu lashed a backhand across court to recover to 5-5.
Ishizu did well to save three break points in the 11th game, to lead 6-5, and Robson crumbled on her serve in the next, dropping the set by slicing a backhand wide.
After five breaks of serve in the first set, another two followed immediately in the second.
Robson saved two break points in the sixth game, but not a third, and Ishizu edged 4-2 ahead, two games away from the final.
With the match seemingly getting away from her, Robson delighted the crowd by hitting back immediately, and then breaking serve once more to lead 5-4.
A superb forehand gave her two set points but she threw the chance away over the course of four poor points.
Robson flung her racquet to the ground as her frustration mounted and although she built up a 5-2 lead in the tie-break which soon followed, Ishizu reeled off five points in a row to win.