Kunlavut Vitidsarn is bidding for a third consecutive title at the BWF World Junior Championships ©BWF

Thailand's Kunlavut Vitidsarn moved a step closer to claiming a third successive men's singles title at the Badminton World Federation World Junior Championships by beating Chinese Taipei's Liao Jhuo-Fu in the last 16 in Kazan.

Vitidsarn triumphed 21-16, 21-14 at the Kazan Gymnastics Centre in the Russian city and will now meet sixth-seeded Indonesian Bobby Setiabudi, who overcame China's Dong Tian Yao 21-23, 21-18, 21-10.

There was a surprise exit, however, for third-seeded Chinese Liu Liang as he fell to a 21-14, 19-21, 20-22 defeat at the hands of Indonesia's Yonathan Ramlie.

Awaiting Ramlie in the quarter-finals is Malaysia's Shahyar Shaqeem, who beat Chinese Taipei's Su Li Yang 13-21, 21-16, 21-14.

Also through to the last eight is fourth-seeded Chinese Li Yun Ze, a 21-14, 19-21, 21-17 winner over Thailand's Setthanan Piyawatcharavijit.

Next up for Li is Malaysia's Goh Wyman after he defeated Hong Kong's Jason Gunawan 9-21, 21-19, 21-16.

Completing the schedule for the quarter-finals is a clash between 10th-seeded Frenchman Christo Popov and unseeded Chinese Ren Cheng Ming.

Popov overcame Chinese Taipei's Lin Kuan-Ting 21-11, 22-20, while Ren secured a 21-15, 21-13 victory over India's Rohan Gurbani.

In the women's singles event, top seed Phittayaporn Chaiwan progressed through to the quarter-finals by beating Russia's Anastasiia Shapovalova 20-22, 21-14, 21-15.

Next up for the Thai is Japan's Akari Kurihara, who defeated fifth-seeded Chinese Han Qian Xi 21-11, 21-11.

Second seed Zhou Meng of China is also through to the last eight after overcoming Japan's Chihiro Uchiyama 21-18, 21-15.

Standing between her and a place in the semi-finals is Indonesia's Stephanie Widjaja, a 21-12, 21-16 winner over sixth-seeded Hungarian Vivien Sándorházi.

The most notable casualty from the women's singles was third-seeded Thai Benyapa Aimsaard, who lost 21-12, 17-21, 11-21 to Chinese Taipei's Hung En-Tzu.

Hung's reward is an encounter with China's Dai Wang following her 21-18, 17-21, 21-12 victory at the expense of eighth-seeded Indonesian Yasnita Enggira Setiawan. 

The one other quarter-final tie will see fourth-seeded Indonesian Putri Kusuma Wardani face seventh-seeded Japanese Riko Gunji.

Wardani beat India's Aditi Bhatt 21-11, 21-15, while Gunji defeated China's Tan Ning 13-21, 21-13, 21-19.