The experienced Smriti shot her second successive two-under 70 to finish with a total of 214, as against Nalini Singh's 218 following a final round 75.
Saaniya Sharma (73) finished third at 224, Shraddhanjali Singh (71) was fourth at 225, while Vani Kapoor (76) was fifth at 226 and Neha Tripathi (78) was sixth at 227.
Ankita Tiwana (75) and Meghna Bal (77) were tied for seventh at 232.
Nalini, leading by one shot overnight, failed to land any birdies through the round. She bogeyed the third and fourth and fell behind.
When Smriti birdied the fifth and then eighth, Nalini was virtually out of the race.
Smriti bogeyed the 10th and Nalini bogeyed the 17th. Then Smriti ended the tournament in style with a birdie on 18th to finish at 70 and 214. Nalini was just not able to hole her putts and had three bogeys.
Saaniya had two bogeys and one birdie in her 73, while Vani once again disappointed with a 76.
Shraddhanjali (71) had a sub-par round during a week when her fortunes fluctuated wildly with rounds of 75, 79 and 71.
This was the first-ever women's professional event at the picturesque Royal Springs Golf Course, which presented a huge challenge for the golfers.
Smriti became the first multiple winner this season, as she had also won the second leg in Bangalore before this one. Sharmila Nicollet won the first leg, while rookie Vani took the third.
The fifth leg will be held at the DLF Golf and Country Club September 19.
