Peng,28,was seeking to follow Li and become only the second Chinese player to reach a grand slam final. However,the bid finished with her being taken from the court in agony,in tears,and in a wheelchair.
Peng was trailing Denmark's Wozniacki 7-6 (7/1) 4-3 when she left Arthur Ashe Stadium to seek treatment - believed then to be for cramping - and play was held up for 10 minutes.
She returned,but soon collapsed and was escorted away.
Peng's withdrawal was one of the most discussed topics on Sina Weibo,a Chinese microblogging service similar to Twitter.
"Hang in there,Shuaishuai,"one post read,referring to the star affectionately by repeating her name twice.
"You are the pride of the Chinese people!"
Communist Party mouthpiece People's Daily praised Peng in a comment on its Sina Weibo account,saying"there is no loser today ... thank you,Shuaishuai,you tried your best!"