The Indian Thapa came into the men's under-63.5 kilogram tournament as one of the favourites, but the 2015 world bronze medallist required a 3-2 split decision his way with victory over Byambatsogt Tuguldur of Mongolia.

In the same category, Turkmenistan's Hursand Imankuliyev won by a 4-1 split over Cambodia's Ratha Ven, while Bakhodur Usmonov of Tajikistan defeated Thailand second seed Somchay Wongsuwan on a 3-2 split decision.

Uzbekistan's Khalokov, who won world silver last year in Belgrade, eased past Iraq's Mohammed Anwer Jasam by unanimous decision in the men's under-57kg tournament.

A Youth Olympics and Youth World Championships gold medallist from 2018, he will progress as one of the favourites.

Joining him in the next round is Gantumur Lundaa of Mongolia, who convincingly beat Dorji Nima of Bhutan, and Cheng-Wei Lee of Chinese Taipei who defeated second seed Khusravkhon Rakhimov of Tajikistan by a 4-1 split decision.

From one youth great to another, Kazakhstan's Sanzhar Tashkenbay was the clear winner by unanimous decision in the men's under-48kg tournament - beating Asilbek Jalilov from Uzbekistan.

Orkhontungalag Unubold also won by unanimous decision in the category by beating Philippines' Mark Lester Durens.

Adkhamjon Mukhiddinov of Uzbekistan and Mongolian Bayarkhuu Buyandalai both won their respective under-60kg bouts by referee's stoppage - eliminating Paul Julyfer Bascon of the Philippines and Mohamad Zulkhailene of Malaysia respectively.

Aslanbek Shymbergenov, an Asian Games silver medallist, picked up another win for Kazakhstan in the men's under-71kg tournament by beating Marjon Pianar of the Philippines by referee's stoppage.

In the same weight class, India's Sachin won by unanimous decision against Peerapat Yeasungneon of Thailand, while Amit Kumar was another Indian to progress in the under-67kg category by beating Zheng-Rong Huang of Chinese Taipei by unanimous decision.