After going 52 holes without dropping a shot at the Delhi Golf Course (DGC), his bogey-free run came to an end on the 17th but a two-under-par 69 was enough to finish ahead of holder Siddikur Rahman on 12-under 201.
“I missed with my eight-iron on the 17th or else I would have still been bogey-free,” said Chawrasia who claimed both his previous European titles on home soil.
“I want to think and play positive on the final day. The final round is always special so I will play aggressively,” he told reporters.
Chawrasia, the son of a greenkeeper, made a birdie-birdie start and got a lucky break on the eighth when his tee shot deflected off a tree and bounced 40 metres to the edge of the fairway.
Bangladeshi Siddikur, who won the trophy two years ago before it was co-sanctioned by the European Tour, also birdied the opening hole but fell four shots behind after a double bogey on 15.
“I had a nice rhythm and picked up a couple of shots until the double bogey,” the DGC specialist said after his 70.
“I managed to recover well and made a great par save on 17 and then managed to birdie the last so overall I am happy with one-under today.”
In his 11 starts at the DGC, Siddikur has won once at the 2013 Indian Open and registered another nine top-10 finishes.
“The birdie at the last was very important. Anything can happen in this game. I am looking forward to tomorrow and hopefully I can play the way I did on Thursday,” he said.
Australian Marcus Fraser was third on 206 after a 67.
Indian-born Swede Daniel Chopra made a brilliant eagle on the par-five 18th to card a 65, the lowest round of the day, and join Thai Prayad Marksaeng on 207.
Spaniard Miguel Angel Jimenez returned a second successive 71 to close on 212.
(Reporting by Amlan Chakraborty, editing by Tony Jimenez)