Lahiri, who needed to win or finish in top four to keep alive his hopes of the Order of Merit, ended sixth and that handed the OOM to David Lipsky, who himself ended 38th.
Lahiri started with a birdie on second, but the double on fourth followed by sixth, eighth and ninth besides birdies on fifth and seventh meant he turned in 38.
Lahiri's only consolation of the day was that he sealed his place at the 2015 British Open at St. Andrews with as he was one of the four players who are not otherwise exempt for the world's oldest Major next year.
It will be Lahiri's third appearance at the Open, after having played it in 2012 and 2014.
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"At least for my consolation I earned a spot at The Open next year. That would put some balm on my wounds. I've had a great year and I have a lot to look forward to," he added.
England's Lee Westwood staged a brilliant final round fight back with a five-under 67 to win the USD one million Asian Tour event.
The former world number one won the inaugural edition in 2011 and made it another victory to remember by signing off with a four-day total of eight-under 280 at the Amata Spring Country Club.
Gaganjeet Bhullar (72) was the next best Indian at tied 45th with a total of seven-over 295, while SSP Chowrasia (75) and Chiragh Kumar (73) were tied 55th at 10-over 298 and Arjun Atwal (78) slipped to tied 65th at 12-over 300.