Shashi defeated Uzbekistan's Durdonakhon Rakhmatova in a unanimous verdict, while Vanlalhriatpuii went down to South Korea's Im Aeji in a split verdict in her opening bout.
Shashi was in action in the first session and grabbed the early advantage by taking the lead in launching attacks. The following two rounds followed a similar script as Shashi got the judges' unanimous nod.
The gold-medallist fromBalkan Youth International Championship, will next face the Chinese Taipei's Lin Li Wei- Yi, who got a first-round bye.
The Korean broke through Vanlalhriatpuii's defence quite early and although the Indian fought back hard in the closing three minutes, the bout had tilted decidedly in Aeji's favour.
Aeji will next face Bulgaria's Mehmedova Aslahan Sezgin in her prequarterfinal bout.