Sumit Sangwan (91kg) and Amit Phangal (49kg) were the other two Indian boxers to book medals as well as World Championship slots in the prestigious continental event.
However, sixth seed and former Commonwealth Games gold- medallist Manoj Kumar (69kg), Gaurav Bidhuri (52kg) and Kavinder Singh Bisht (49kg) bowed out of medal contention after losing their respective quarterfinal bouts. But the trio remains in the hunt for berths in the September-October World Championship to be held in Germany.
Vikas, on the other hand, was the lone silver-medallist for India in the 2015 edition.
Sumit gave India their first win of the day when he stunned third-seeded Chinese Fengkai Yu 4-1.
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The former Asian Olympic Qualifiers' gold-medallist put his long reach to effective use against an opponent, who was thrown off-balance every time he tried to attack.
Sumit will now face second seed Jakhon Qurbonov of Tajikistan in the semifinals on Friday after a rest day tomorrow. Qurbonov outpunched Pakistan's Mehmood Sanaullah in his quarterfinal bout.
Although Langu was clearly the more attacking of the two boxers but was mostly found wanting on accuracy.
Amit is up for a tough one in the semifinals, where he will square off against Uzbekistan's Olympic gold-medallist Hasanboy Dusmatov.
Shiva, meanwhile, sailed past Chinese Taipei's Chu-En Lai in his quarterfinal bout.
Shiva was clearly the superior of the two boxers in footwork and accuracy. The Indian, who is also a World Championships bronze-medallist, left Lai befuddled with his counter-attacking approach.
Vikas was up against Indonesia's Brama Hendra Betaubun. Though Betaubun was quite a match for Vikas in aggression, the Indian dominated by not just defending well but also by using his right hook to good effect.
Vikas will now face fourth seed Dongyun Lee of Korea in the semifinals.
However, it was heartbreak for Gaurav, Kavinder Bisht and Manoj.
Gaurav, who opened the proceedings for India in the morning session, lost to second-seeded Chinese Jiawei Zhang. Kavinder, on the other hand, went down fighting to local favourite Jasurbek Latipov.
Gaurav went down 2-3 in a bout marred by excessive clinching and holding. Both the boxers ended up being warned by the referee for their tactics.
In the end, Zhang came out triumphant with his clean straight punches even though Gaurav had also struck some lusty body blows.
However, all is not lost for either Gaurav, Kavinder or Manoj as they can still claim a place in the World Championships if they win their respective box-offs.