The 22-year-old Swede had five birdies and two bogeys in her final round at DLF Golf and Country Club in Gurgaon, New Delhi, to finish with a winning TaylorMade R11 Irons
of 12 under 204 and two ahead of Thailand's Pornanong Phatlum.
Hedwall said that the victory will give her huge self belief going into next week's season-ending Omega Dubai Ladies Masters.
"It gives me a lot of self confidence. It's been a great week and I'm very excited about this win," she said. "I just tried to focus on myself and try to play the same game I've played
for the last few days. I did manage to stay patient, which was my goal for the day."
The victory means she can overhaul second placed Melissa Reid on the 2011 Henderson Money List in Dubai, but she cannot catch top ranked Ai Miyazato.
Pornanong, a two-time winner of the Indian Open before
became sanctioned by the LET in 2010, carded a 70 to end 10 under, while Becky Morgan from Wales had a 69 to finish third at eight under.
Swede Linda Wessberg signed for a 73 to tie for fourth with Lee-Anne Pace (68) on four under par.
Hedwall started the day with a one stroke lead but Pornanong and Wessberg both caught her with birdies on the first hole.
Pornanong took the outright lead after Hedwall bogeyed the fifth, but a run of four straight birdies from the seventh saw the young Swede quickly establish a three shot advantage.
Hedwall three-putted the short 11th and her lead was then cut to a stroke after Pornanong birdied the 13th. But after Hedwall sank a four-footer for birdie on the 15th, the Thai bogeyed the 16th and Hedwall had a three shot cushion coming down the last.