Top seed Yuki Bhambri's [ Images ] title hopes went up in smoke after a stunning straight-set defeat to unseeded local favourite Chase Buchanan in the boys' singles quarterfinal of the US Open [ Images ].

The match, delayed by a day due to persistent rain ended in a heartbreaking 3-6, 6-7 (4-7) loss for the Indian, who had not dropped a set this far in the hard court event.

The match was shifted to indoor courts and the changed conditions perhaps adversely affected the reigining Australian Open [ Images ] champion.

The world number one junior has already crashed out of the doubles event following a shock first round defeat with his Taipei partner Liang-Chi Huang.

Buchanan then went on to win his semifinal against eighth seed Gianni Mina of France [ Images ] and set up a title clash against Australian third seed and string contender Bernad Tomic.

Photograph: Mohammed Jaffer/SnapsIndia