Chiragh's second successive two-under 70 in the final round was three shots off the pace, while the Australian returned a four-under 68 to end his three-year title drought on the Asian Tour.
Overnight tied second, Chiragh held on to the position with the help of a birdie on the last hole for a four-day aggregate of 17-under 271. With this result, Chiragh also secured his Asian Tour card.
Ross Bain of Scotland and Chinese Taipei's Lu Wei-Chih carded matching 67s to finish tied third with a total of 16-under 272.
SSP Chowrasia turned in a three-under 69 to finish a creditable tied seventh and regain his number one position in the Asian Tour Order of Merit.
A consistent Himmat Singh too brought home a four-under 68 to share the seventh spot with Chowrasia.
Manav Jaini (67) and Anirban Lahiri (69) finished tied 12th and tied 15th respectively with totals of 279 and 280.
Ryder Cup player Edoardo Molinari of Italy carded a 69 to sign off tied 15th, while defending champion Rikard Karlberg (79) endured another difficult day to finish in the bottom half at tied 64th.
Overnight leader Gleeson made a rampaging start to the final round, firing a couple of birdies at the first and fifth, with an eagle sandwiched at the third, to take the turn at four-under.