Hamilton went into the Indian Grand Prix with only a slender chance of finishing his final season with McLaren by claiming the title.
At the end of it, and following a fourth consecutive victory for the dominant Sebastian Vettel in his Red Bull, there is no longer light at the end of the tunnel.
Hamilton finished fourth and now trails Vettel by 75 points with 75 available from the last three races in Abu Dhabi next Sunday, the United States and Brazil.
Put into perspective, ahead of the Singapore Grand Prix where Vettel began his winning streak, Hamilton led the 24-year-old German by two points.
"I'm not happy with the result because I've lost the world title, so it's heartbreaking, but that's the way it goes," said Hamilton.
The result may be one thing, but the performance was another as the 27-year-old Briton came within 0.6secs of a place on the podium.
A woeful start, described by Hamilton as "a disaster, brutal, terrible", let him down and left him searching for answers from his team.
Hamilton said: "I asked the team 'please tell me what I'm doing wrong so I can fix it?'.
"But they've said I'm doing everything right, that it was perfect, so I don't know. It's something we're going to have to investigate."
It resulted in a phenomenal first-lap tussle between himself, team-mate Jenson Button and Ferrari's Fernando Alonso at the end of which Hamilton dropped from third to fifth.
Further issues with the soft-compound tyre and his steering wheel which encountered a downshift failure did not aid his cause, the latter changed along with his tyres in his only pit stop that took just 3.6secs.
But once on the harder tyre in the second half of the 60-lap race, Hamilton and Button were consistently quick, the latter setting the fastest lap on the final lap.
"It was a very tough race, but a great race. Within the car it felt great," said Hamilton.
"It was fantastic at the end. Every second I thought I could catch Mark. You have to believe, and that's why you push.
"But I just wasn't close enough. It's such a shame we didn't have the ultimate pace at the beginning to really challenge the guys in front.
"But I feel proud of myself and proud of the guys."
For Button, after winning the battle of the champions on the first lap, it was not long before he was passed by first Alonso and then Hamilton, dropping to fifth which is where he eventually finished.
"I've never had the start of a race like that before," said Button.
"It was a good clean fight, millimetres between us through the first few corners and I really enjoyed it. It was nice to fight like that and come out on top as well.
"But then I just didn't have the pace and they both came past me. The whole first stint was pretty poor.
"Then when we put the hard tyre on, the car felt really good, but I found it very difficult to get past (Romain) Grosjean.
"I lost so much time behind him, and that was my race over for a better position.
"So the first and last laps were great. It's just a shame about all the others in the middle."