World No.3 Sindhu, the first Indian to reach the finals of the season-ending championship, suffered an agonising 21-15, 12-21, 19-21 defeat from Yamaguchi in a tiring women's singles grand finals match which lasted for over 94 minutes.
The lanky Indian shuttler appeared good to take the gold medal as she dominated the first game with her "jump and smash" and won it 21-15.
The two were neck and neck till the middle half of the first game, but Sindhu was unstoppable after the first break and took points at will as the Japanese could not match her reach and agility.
Yamaguchi made a sensational comeback in the second game and made the Indian fight for every point. Sindhu trailed Yamaguchi 13-11. Widening the lead, the Japanese enjoyed 19-12 dominance over Sindhu.
Yamaguchi continued dishing out an aggressive performance and won the second game 21-15 against Sindhu to take the match into decider.
Determined Sindhu made a good start in the decider game and made her opponent run around the court with her long shots.
Sindhu enjoyed a 4-0 lead in the beginning but made some unforced errors to level it at 5-5.
There were long rallies in the third game as none of the two finalists were willing to give away crucial points.
The Pullela Gopichand protegee maintained the lead till the mid-break but her equally resilient opponent snatched the lead at 17-15 and made it tough for the Indian thereon.
Sindhu looked exhausted and stressed in the decider and lost it 19-21 to settle for silver.
The 22-year-old had earlier outclassed Yamaguchi in straight games in her last Group A match.
Sindhu had set the summit clash against the World No. 2 after defeating Chen Yufei of China in straight games 21-15, 21-18 in the semifinals.(ANI)