Another Indian, Anirban Lahiri, a two-time Asian Tour winner, Arnond Vongvanij of Thailand and Jaakko Makitalo of Finland were a further two shots back in fifth place.
Kapur, who has four top-five finishes on the Asian Tour this season, was delighted to continue his solid form where he posted a flawless round highlighted by five birdies.
"I'm happy but not satisfied. I just wanted to go out there and shoot my heart out. This is my national open and Hero is my sponsor. Obviously I would have liked to win but fourth is not bad. My streak of top-five continues," said Kapur.
Among other Indians in fray, Chiragh Kumar (68) finished tied eighth with a total of nine-under. Former champion Jyoti Randhawa (70) was a stroke adrift at tied 12th.
Rising star Gaganjeet Bhullar (73) finished tied 22nd after his worst card of the week left him four-under overall.
Wiratchant, meanwhile, sensationally won his third Asian Tour title this season by defeating Richie Ramsay of Scotland on the first play-off hole.
Wiratchant, who was playing one flight in front of Ramsay, birdied the last hole in regulation play when his seven iron approach shot landed about one feet from the hole as he closed with five-under-par 66 at the approximately USD 1.25 million Asian Tour event. MORE
