Mary Kom dispatched Smith before the end of the first round with the referee stopping the contest when the score was already 9-0 in the Indian's favour.
The mother-of-two from Manipur, who is also a Khel Ratna awardee, will take on Welshwoman Lynsey Holdaway in the last-eight stage on September 15.
The 25-year-old is just one win away from assuring herself of a medal in the sixth edition of the event.
However, there was disappointment for Neetu in the 60kg category as she lost 2-12 to former world champion Katie Taylor of Ireland.
A vicious right hook in the first round could almost have sealed the contest, but Neetu managed to hold out for the full eight minutes.
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