The 38-year-old Indian began the final round at the DLF Golf and Country Club with a two-shot lead and carded a one-under 71 to close on 10 under par.
World number 258 Chawrasia has now won four European Tour events, all in India.
Scotsman Scott Jamieson shared third place on two under, with only seven men finishing the tournament under par.
Northern Ireland's Michael Hoey carded a disappointing final round of 75 to finish in a tie for eighth position.
Hoey, who lost his European Tour playing card last year, had posted three consecutive rounds of 71 to lie two off the lead but ended the tournament on level par.
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SSP Chawrasia retained the Indian Open with a comfortable seven-stroke victory in New Delhi.