The title would make Antonelli Formula 1's youngest ever champion and Italy's first since 1953.
Antonelli's third place in a Singapore Grand Prix that was controlled from start to finish by Red Bull's Max Verstappen was scrappy, as he flirted with a penalty for testing the track's limits.
But it was enough to extend his lead over teammate George Russell to 102 points, and when asked if he dared to dream of clinching the title in Austin later this month on the long journey home, he said: "For sure.
"But at the same time, I know it's very close, I know it's there, but I just need to make sure that I keep doing the best I can. The mindset is always the same: to go out there and win.
"I think this weekend I haven't particularly driven that well... but I feel confident that, (with) a week to reset, I'm really looking forward to being back in Austin.
"If I don't do my job well, then the result won't come. So in order to achieve what I want, I need to perform at 100%."
Antonelli can mathematically win the championship in Austin on the assumption there are still five races to come after, with the fate of the Grands Prix in Qatar and Abu Dhabi up in the air due to the conflict in the Middle East.
However, Mercedes boss Toto Wolff is refusing to tempt fate.
"I remind myself that this is motor racing and crazy things have happened," Wolff said.
"It probably needs the other two (contenders), George and Lewis (Hamilton), to retire and him winning. So this is not a likely scenario," he added, while recognising that the title was within reach and maybe inevitable.
"It's going to come towards him, whether that's in Mexico or Brazil, or far down the line."
Mercedes upgrades
Russell, who worked his way up from the back of the starting grid due to engine penalties, finished a respectable ninth at the Marina Bay Street Circuit, where overtaking is notoriously tricky.
Wolff said both drivers would probably be running in Austin on an upgraded car as some, but not all, of its teething problems had been ironed out in Singapore.
"I think that this new car needs a very different setup philosophy than the previous car," he said.
"Does it have the performance that we were hoping the upgrade would bring? I don't think so yet, but it was a step in the right direction."
Antonelli narrowly avoided a five-second penalty, hitting the maximum limit of breaches of the track boundaries.
However, Wolff praised his driving and joked about how he could boost the diminutive driver higher for a better view of the track edges.
"I have a good strategy. I'm going to put a pillow from the hotel under his arse, so he can actually see the road."