The 18-year-old Indian, who had a share of the lead on the first day and was third after day two, opened with three bogeys in a row and was never able to make ground on the overnight co-leader Thailand's Prima Thammaraks (73).
Prima claimed her first professional victory beating Australian Sarah Jane Smith by one shot in the Australian LPGA Tour event.
Sarah (68) was the only player to shoot under 70 on a tough final day.
She will now play Oates Victoria Open next week, the opening event of the Ladies European Tour in 2017.
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After three bogeys in first three holes, Aditi did have three birdies on fourth, 12th and 18th, but she also dropped shots on seventh, 11th and 13th holes.
Vani Kapoor, the other Indian, who made the cut, shot 77 after rounds of 73 and 79 on first two days. She finished tied-38th.
Prima, started the day tied for the lead at six-under par with her 18-year-old compatriot Paannarat Thanapolboonyaras. She quickly zipped ahead with birdies on the 3rd, 5th and 6th holes to take a four-shot lead over the rest of the field.
She dropped a bogey on seventh and that was followed up by a double bogey at the 8th. When she bogeyed the par-5 ninth, her lead was down to one. She needed a birdie on final hole to win and she did that from 20 feet.