With sheer pace and tenacity, a swarm of red shirts caught Mandeep Mor and co. unawares early in the contest - and kept the brakes on the dangerous Indian forward-line with some superbly-timed tackling and deft interceptions to record a memorable upset at the Sultan of Johor Cup.
The Japanese were very nearly there in the second encounter against Great Britain but were undone by a controversial goal which only inspired them to give it their all against an Indian side who had looked in prime form against New Zealand on Sunday.
A minute's silence was observed in memory of the junior hockey players who were killed in a tragic accident in Madhya Pradesh before the Indians took the field as firm favourites against Japan.
Few saw it coming after a scintillating 8-2 win against the Junior Black Sticks, but coach BJ Kariappa's boys seemed unprepared to handle the intensity of the Japanese and succumbed by a 3-4 margin and being 1-4 down midway through the third quarter.
To round off the proceedings, which exemplified Japan's brilliance on the day, Kosei Kawabe did a Lalit Upadhyay - picking up a long overhead pass one bounce and punching it past the goalkeeper with a flat stick mid-air, much like the Indian striker had done against South Korea in the Asian Games last year.
At the end of the third day, it was Great Britain's turn to sit pretty on top of the heap after getting past Australia by a lone goal - and the Indians now face an Aussie side who need to win both their remaining matches to make it to the finals.
The Australians who drew against Malaysia earlier are third in the table with four points while the Indians are second with six. Great Britain is the only unbeaten side with nine points from three games.
It was not as if the Indians lowered their guard against Japan - except perhaps in the first minute when the Junior Samurai scored off a PC following a defensive lapse.
What was concerning was the inability of the Indians to play their natural game as a result of being cramped for space up front - an obvious deficiency which their adversaries will now attempt to exploit in the crucial matches ahead.
Whether or nor the Indian think-tank can come up with an effective strategy to outmanoeuvre a cornered Australian side remains to be seen, but hockey fans can look forward to a peach of a contest when the two old rivals clash with all to play for at Johor Bahru.
The Indians were thrashed 0-4 by the Australians in a U-21 invitational in Madrid earlier this year but will take heart from the fact that they got past the same side by a 5-4 margin in a pulsating encounter at the same venue last October.
Here is how you can catch all the action:
Event: Sultan of Johor Cup, 2019
Venue: Johor Bahru, Malaysia
Date: 16 October 2019
Time: 1:35 pm Indian Standard Time (IST)
Telecast: No telecast in India
Live Streaming: Notthefootyshow
The Indian defence has looked vulnerable and BJ Kariappa's side may need to crowd their own circle - particularly since the Aussies are likely to play all-or-nothing hockey in an encounter they cannot afford to lose.
If the Indians maintain their healthy PC conversion rate and manage to outdo the Aussies on the counter, getting past the finish line is very much on the cards.
Score Prediction: India 4 - Australia 3