India held out for 90 minutes and were on course for qualification for the knockout stages.
But an error by their goalkeeper led to a foul by captain Pronay Halder from which Bahrain scored the winner from the penalty spot.
It was a harsh lesson for Stephen Constantine's team.
But they paid dearly for their lack of progress in attack.
No shots on target from the entire match told that story.
However, the Blue Tigers showed enough potential to be a force in Asia in the future.
Apart from a weakness in goal, they have solidity at the back around the tall Sandesh and athletism in midfield.
Though he didn't threaten in this match Sunil Chhetri is capable of converting up front.
What they lack is that initiative and anticipation of more experienced teams.
They came really close to realising a mainly defensive plan but just fell short.
Perhaps next time it will be different, based on the undoubted potential within the country.
Meanwhile Bahrain joined Thailand and hosts UAE in the Round of 16.