Lahiri, starting the final day, four shots clear of the field, dropped a crippling quadruple bogey on par-5 third hole and that in a single hole wiped away his overnight lead.
Last week Lahiri lost a play-off after seven birdies in a row in last seven holes in Macao.
Justin Thomas (64), meanwhile, birdied two of the first three holes and went ahead and then kept his foot on the pedal to retain the CIMB Classic title that he won 12 months ago.
The only consolation for Lahiri was a good start to the 2016-17 season, which also produced his career-best finish at tied 3rd, bettering his tied 5th at 2015 PGA Championships.
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When the round ended, Thomas was 23-under and in second was Japan's Hideki Matsuyama (66) with a birdie-birdie finish for 20-under, while Lahiri tied for third with Derek Fathauer (67) at 19-under in the USD 7 million event sanctioned by the Asian Tour and PGA Tour.
A win with a purse of USD 1,26 million would have also sealed for Lahiri a second straight Asian Tour Order of Merit and secured a move into top-50 of the World Rankings and also got him his Masters invite.
But on the final day, the quadruple bogey on the third, where his playing partner Thomas birdied for a five-shot swing was just too much to keep the title hopes going.