Phatlum, who celebrates her 23rd birthday on Tuesday carded a final round of six-under 66 to set a new tournament record of 13-under 203, beating by one, the total achieved by Caroline Hedwall in 2011.
Hedwall, who set a new course record on Saturday, was a distant second following a final round of 69, that gave her a total of nine-under 207, four behind the winner.
Aditi Ashok was the best from the host country with rounds of 69, 74 and 72.
"This was an amazing experience, something that I will cherish. Playing with top stars from Europe and Asia and finishing in top-10 was almost like a dream," said Aditi, who plays the All India juniors next week and then defends her All India Ladies title in Kolkata the following week.
The top Indian pro was Nalini Singh Siwach (73-74-74) in tied 33rd place, the same as where she started the final round.
"I could have done better, but this will give me some confidence as I leave for Morocco to play in the Ladies European tour Q-School," she said. More