BIRMINGHAM (AFP) - Ratchanok Intanon, the youngest ever badminton world singles champion, moved to within one win of a probable All-England Open showdown with Olympic champion Li Xuerui, but admitted that her patchy form is scary.
The 19-year-old Thai coming from behind for the second day in succession, edging Han Li, the world No. 19 from China, by 18-21, 21-14, 21-11. The day before, she was within three points of defeat against Singapore's Gu Juan.
Honing her survival instincts in this way despite a patchy performance may be crucial, as she admitted that the seven months since she overcame Li in the World Championships final have been hard to handle.
"Everyone has been trying to beat me, and I have been putting myself under pressure and been scared of the losses," she said. "So I try to concentrate on practising. I try not to think about the world championships because I am not the world No. 1."
That of course is Li, who also made a great escape for the second successive day, coming from a game and 8-13 down against Japan's world No. 16 Minatsu Mitani, before winning 14-21, 21-19, 21-15.
Li had saved a match point on Wednesday against Busanan Ongbumrungpan, the world No. 17 from Thailand, and the Chinese player again proved mentally and tactically resourceful as she turned the tide.
"It's a difficult situation when your opponent has a lead," admitted Li. "Both my coach and myself were telling me to keep fighting."
Li next plays Sung Ji Hyun, the fifth-seeded South Korean who reached the final of the Denmark Open five years ago. Ratchanok will play Michelle Li, the world No. 24 from Canada.
Saina Nehwal, the seventh-seeded Commonwealth champion from India, also struggled before clinching a 24-22, 18-21, 21-19 win over Zhang Beiwen of the United States.
However, there were no such worries for Lee Chong Wei, the men's world No. 1 from Malaysia, who overcame his compatriot Chong Wei Feng 21-6, 21-12.
Lee, who hopes to win the title in what may be his last All-England campaign, will play Kento Momota, the world No. 15 from Japan.
Lee's main rival, Chen Long, the second-seeded title-holder from China, resisted a late fight-back by Takuma Ueda, the world No. 17 from Japan, to also reach the quarter-finals.
Ueda had raced back to 19-19 and to 20-20 in the second set, before Chen made a couple of big smashes to secure a 21-14, 22-20 win.
Chen now plays Hans-Kristian Vittinghus, the world No. 21 from Denmark, who beat Boonsak Ponsana 18-21, 21-12, 21-19.