"I didn't move well at all in the match, I was thinking too hard," said the fourth seed.
Though she remained in the medal hunt, a win would have fetched a dream entry to the finals, which would have given Saina a chance to aim for Gold. Now, she faces Wang Xin of China on Saturday for the bronze medal.
Saina playing against World No 1, fought very well in both the sets, but couldn't go past the unlucky 13, as she registered 13-21, 13-21 in both the sets to go down in the semi-final.
The margin of error was very less, as Yihan was sharper, accurate and also used powerful smashes to outclass Saina Nehwal.
Saina committed a few errors during the first set as she lagged behind, 6-11 and then fought hard to reach 13, but the Yihan was very good, as she stormed to 21 and took a 1-0 lead.
Though she fought well in the second game, Saina couldn't stop the Chinese, as Saina said, she 'was thinking too hard' and did not move well in the match.
The victory against Saina also marked Yihan's sixth victory against the Indian in six matches.