The Mercedes driver held off a late surge from Max Verstappen to win in Suzuka and open up a 59-point gap on his main championship rival Sebastian Vettel - who retired with a spark plug failure.
Verstappen finished a close second with Red Bull team-mate Daniel Ricciardo completing the podium, but it was all about Hamilton here.
He can claim the title in a fortnight at the US Grand Prix if he wins and Vettel finishes sixth or lower. Even second place would be enough for Hamilton if the German came home ninth.
In a season where he surpassed Michael Schumacher’s pole position record - this was his 71st time starting first - Hamilton can move onto four world titles.
That would make him the most decorated Briton in F1 history and move him into a category where only Schumacher (seven world titles), Juan Manuel Fangio (five), Alain Prost (four) and Vettel (four) reside.
Contrastingly, just six weeks ago Vettel was top of the championship.
Now he requires something special to happen if he is to claim his fifth crown, and Hamilton can scarcely believe where he is positioned with just four races remaining.
“I think it is unbelievable really to think that we are where we are,” he said.
“I could only have dreamed of having this kind of gap. All I can really say is that I have to put it down to my team. They’ve done a phenomenal job.
“There is still a long way to go, 100 points is a lot of points and anything can happen. I just need to keep my head down.”
Hamilton secured his last title in Austin two years ago and has won the last three races at the Circuit of the Americas.
He does not need to win another race between now and the season’s end to sew up the title but he is not about to let up.
“To be honest there is not really any need to change my approach,” he said.
Vettel’s spark plug problem was identified as his Ferrari was fired up yesterday morning and, despite taking the start from second on the grid, it was soon evident it would prove his undoing.
He was passed by Verstappen, Ricciardo, Esteban Ocon and Valtteri Bottas in the first lap and was called in to retire on lap five.
That follows an engine issue a week ago in Malaysia which saw him start from the back of the grid and recover to fourth, and a first-corner crash in Singapore that left both Ferraris out of the race.
But Vettel refused to point the finger of blame at his team and insists he will continue his fight until the last.
“It’s normal to be critical, especially if things go wrong because it’s part of our job,” he told Sky Sports F1.
“But I need to protect them (Ferrari). They have done an incredible job so far. It’s just a pity in the two races with the reliability issues.
“We still have a chance this year. Obviously it’s not as much in our control as we like but overall I think the team is in a good way.”