Ratchanok Intanon began her title defence with a victory over Gregoria Mariska Tunjung in the first round of the Malaysia Masters yesterday.
Playing in her first tournament of 2019, the Thai sixth seed defeated Tunjung of Indonesia 21-15, 21-16 in 38 minutes at Axiata Arena in Kuala Lumpur.
She will play Chloe Birch of England today in the second round of the BWF World Tour Super 500 event.
Top seed and world No.1 Tai Tzu-ying advanced to the last 16 round with a 21-9, 21-11 win over Cheung Ngan Yi of Hong Kong.
Ratchanok, who beat Tai in the title match last year, could meet the Taiwanese star in the quarter-finals.
Meanwhile Busanan Ongbamrungphan failed to progress, losing 15-21, 15-21 to fifth seed He Bingjiao of China.
In another setback, Nitchaon Jindapol, the other Thai player in the women's singles event, lost 19-23, 23-25 to fourth seed Carolina Marin of Spain.
In other results, second seed Nozomi Okuhara, seventh seed Saina Nehwal of India and eighth seed Sung Ji-Hyun of South Korea all advanced.
In the men's singles event, Kantaphon Wangcharoen progressed after beating England's Rajiv Ouseph 21-19, 21-13. Kantaphon will play fourth seed Son Wan-Ho of South Korea in the second round today.
Suppanyu Avihingsanon also advanced after rallying to beat Taiwan's Wang Tzu-wei 11-21, 21-17, 21-12. He will face a tough match against second seed Shi Yuqi of China today.
Compatriot Khosit Phetpradab, however, went out at the hands of sixth seed Anthony Sinisuka Sugiarto of Indonesia 21-18, 9-21, 10-21.
Kittinupong Kedren and Dechapol Puavaranukroh rallied to beat South Korea's Kang Min-Hyuk and Kim Won-Ho 20-22, 21-11, 21-14 to reach the men's doubles second round.
Puttita Supajirakul and Sapsiree Taerattanachai, who won the Princess Sirivannavari Thailand Masters on Sunday, were the only Thai survivors in the women's doubles event after they beat Agatha Imanuela and Siti Fadia Silva Ramadhanti of Indonesia 21-13, 21-9.
Seventh seeds Jongkolphan Kititharakul and Rawinda Prajongjai and Chayanit Chaladchalam and Phataimas Muenwong both lost.
