Gold Coast Commonwealth Games gold medallist Saina Nehwal and H.S Prannoy entered the semi-finals while Kidambi Srikanth and Rio Olympics silver medallist P.V Sindhu crashed out of the Badminton Asia Championships here on Friday.
Saina outplayed Lee Jang Mi of South Korea 21-15, 21-13 in the women's singles match which lasted around 40 minutes while Prannoy edged past second seed Son Wan Ho South Korea 18-21, 23-21, 21-12 in the men's singles marathon match of one hour 12 minutes.
The disappointments of the day were Sindhu and Srikanth. Third seed Sindhu lost to seventh seed Sung Ji Hyun of South Korea in straight sets 21-19, 21-10.
Top seed Srikanth was outplayed by fifth seed and veteran player Lee Chong Wei of Malaysia 21-12, 21-15 in just 31 minutes.
"I was upset about my performance today, Lee played very well. I did badly in net lifts and drives, and moved slowly on the court," Srikanth was quoted as saying by Xinhua news agency after his defeat.
The 35-year-old Malaysian said: "Srikanth didn't play at his level today, too many errors in the game. It was different from our last meet at the Commonwealth Games." Chong Wei had lost to Srikanth in the mixed team final of the Gold Coast CWG earlier this month.
Meanwhile, Chinese shuttler Chen Long celebrated a hard-fought victory, bouncing back from one game down to eliminate eighth-seeded Ng Ka Long Angus 22-24, 21-15, 21-17 to reach semi-finals, reported Xinhua news agency.
The two players traded the lead six times in the thrilling decider. The home favourite Chen lost five points when leading by 13-9, and then won five points in a row to reclaim the lead.
Although he missed the first two match points at 20-15, he eventually wrapped up the match in one hour 26 minutes.
"I didn't play well when taking the lead on the court, made too many mistakes. But anyway, winning a close game like this can always make me happy," the 29-year-old said.
Chen will face Prannoy in the semi-finals.
In the semi-final, Saina will meet top seed Tai Tzu Ying, who cruised past home star He Bingjiao 21-14, 21-9.
Another home player Chen Yufei, sixth seed, overcame her Hong Kong compatriot Cheung Ngan Yi 21-18, 21-12.vance.