Overnight leader Shamim Khan of Delhi finished one stroke behind in second position which was enough to seal the 2012 Rolex Rankings (PGTI Order of Merit) title.
Chowrasia (72-70-69-68), who was overnight tied fifth, overcame a four-shot deficit on the final day to claim his 13th professional win, and first at home.
"It's great to win on my home course for the first time and that too coming from behind. I focused a lot on my putting today and it paid off," Chowrasia, who bagged the winner's cheque of Rs 19,81,250, said.
Chowrasia's round of 68 was the joint best score of the day as the 34-year-old was even-par after the first nine holes having made birdies on the fourth and sixth and bogeys on the third and seventh.
Then he found the green in two on the par-5 fourth hole and narrowly missed his 15-feet putt for eagle. He missed the greens on the third and seventh holes.
Chowrasia turned the tables on leader Shamim with birdies on the 12th and 13th as the latter dropped five strokes from the sixth to the 11th.
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Chowrasia landed his approach shot within four feet on the 12th and followed that up with a 12-feet conversion on the par-3 13th.
The two-time winner on the European Tour showed his class once again by making a two-putt from the fringe for birdie on the 15th and sinking a 15-footer for birdie on the 17th.
Shamim Khan (70-68-69-73) finished runner-up to ensure his top position on the Rolex Rankings at the end of the season. MORE