By The Nation
The world No 8 displayed her superior all-court game to beat the Thai No 4 21-16 21-13 and make it six wins out of six against her, dating back to the Thailand Open in 2013.
Ratchanok, the 2010 winner, has now won seven successive matches without dropping a game in 2019, including five at the Malaysia Masters, which she won last week.
She will next play the third seed and world No 5 Chen Yufei of China, who leads her 7-2 in their lifetime record.
Also booking a spot in the quarter-finals was Pornpawee Chochuwong, who scored an upset win over fourth-seeded Akane Yamaguchi of Japan (21-18 21-12) but Thai No 2 Nitchaon Jindapol was eliminated by Chinese sixth seed He Bingjiao 21-17 21-18.
The eighth-seeded women’s pairing of Jongkolphan Kititharakul and Rawinda Prajongjai reached their first quarter-final this year, edging out Chow Mei Kuan and Lee Meng Yean of Malaysia 19-21 23-21 21-14.
In the men’s singles, Kantaphon Wangcharoen lost to 2016 Olympic champion Chen Long of China 21- 19 21- 10 and in the mixed doubles, Dechapol Puavaranukroh and Sapsiree Taerattanachai, after back-to-back finals in Bangkok and Kuala Lumpur, were halted in the second round by Chinese duo Lu Kai and Chen Lu, 21-23 21-15 21-18.