Kapur, lying tied second at nine-under after three rounds, finished at six-under 274 and picked up USD 19,695 as his winnings.
Also tied at 12th was Anirban Lahiri (69).
Up at the top, Spanish veteran star Miguel Angel Jimenez held off Thailand's Prom Meesawat and Stuart Manley of Wales in the first-hole of a sudden-death play-off.
It was a record-equalling fourth Hong Kong Open for Jimenez.
Jimenez, who will turn 50 in January, successfully retained the title after a dramatic day at the Hong Kong Golf Club when he exquisitely rolled in a 15-foot birdie putt on the 18th green to reduce Prom to a second play-off loss in three weeks.
The wily Spaniard rewrote a slice of his own history in becoming the oldest winner on the European Tour at the age of 49 years and 337 days and also became the second oldest winner on the Asian Tour.