Thanks to the convincing win, India, with six points, stayed very much in contention for winning a berth in next year's AFC Challenge Cup.
Chhetri found the net on the 49th and 91st minute while the other two goals were scored by Clifford Miranda (68th) and Jewel Raja (80th) at the Youth Training Centre.
The Indians were completely off colour in the first half, but came out all guns blazing after the change of ends, with Chhetri leading from the front.
The second one came in the 68th minute, this time, Miranda blasting home his left-footer after being set up by Mehtab Hossain.
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Jewel placed the third goal to perfection after being found unmarked inside the box by substitute CK Vineeth while Chhetri scored the fourth, heading in a Mehtab corner in the 91st minute.
It was a tactical display by the Indians against an opposition, who looked ultra-defensive at times. Finding it difficult to break free among the crowd of legs, the Indians preferred to use the flanks in the second half and open up the rivals.
India had defeated Chinese Taipei 2-1 in their opening match of the AFC challenge cup qualifiers.