It was a come-from-behind victory after trailing 1-2 for the better part of the third quarter.
Dilpreet scored in the 11th and 53rd minute for the winners while Sukhjeet's strike came in the 41st minute.
Kyohei Ogawa (23rd, 31st) scored for Japan.
India started on a bright note, attacking constantly in the first quarter. It was in the 11th minute that India's efforts were rewarded with Dilpreet capitalising on a defensive lapse.
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They were awarded a penalty corner in the 23rd minute when the ball hit the foot of an Indian player inside their circle.
Japan's Kyohei Ogawa converted the penalty corner as he brought the teams level on 1-1 after the second quarter.
The Japanese maintained a good rhythm going into half- time Ogawa scored his second of the match to give Japan a 2-1 lead in the 31st minute.
However, the young Indian team showed their character in the latter part of the third quarter when they restored parity through a penalty corner converted by Sukhjeet in the 41st minute to level the scores at 2-2.
India will now face Malaysia in their second match on October 23rd.