The race that took Kimi Antonelli to the brink of a record-breaking world championship was, in the words of his Mercedes team boss Toto Wolff, "the best he has delivered so far" and "the race of a champion who isn't the champion yet".

Not yet. Not quite. But so very near.

The 20-year-old Italian's victory in the United States Grand Prix puts him in an impregnable position.

Antonelli is so far ahead in the points that the only way he could not win the title in Mexico City next weekend is if either his team-mate George Russell or Ferrari's Lewis Hamilton win the race. Even then, Antonelli will guarantee the title if he finishes ninth, or 10th if it's Hamilton.

He arrived here thanks to one of the most dominant victories of the season, in a car in which Russell could finish only eighth, albeit hampered by a five-second penalty.

"Exceptional," Wolff said, "and I think he's outperformed the car."

Antonelli came to Austin already in a strong position in the championship, knowing he would clinch the title if he won with Russell finishing lower than eighth and Hamilton lower than fourth.

He achieved his part of the bargain but Russell and Hamilton did just enough to keep things alive until this coming weekend. Russell was eighth and Hamilton fourth.

Some drivers tighten up when they get this close to achieving their lifetime's ambition. Not Antonelli. He said he was going to treat this like any other weekend, but it wasn't just talk. It's exactly what he did.

"He comes in," Wolff told BBC Sport after the race, in a conversation after finishing his official news conference, "sits on my chair, feet up, and keeps chatting away and saying: 'This is so funny. I'm not thinking about the championship at all.' And in a kind of youngish excitement, almost like it's surreal. And that's why it's not so important."

Did Wolff think that was because Antonelli's lead was so large that he had no need to feel any pressure, or was it innate?

"The advantage helps," he said. "But it's also innate in him and I don't think that it's something to be trained for. He's not over-thinking it."

Wolff's claim about this being Antonelli's best performance so far might surprise anyone who watched him win his home grand prix at Monza from 19th on the grid.

When this was pointed out, Wolff replied: "My problem is that I don't remember past races. So now you're saying Monza was actually also pretty good, obviously with the advantage of the home crowd and seeing all these tifosi that were a little bit confused, wearing red, and an Italian with the Mercedes outfit up on the podium. And I think we're going to see more Kimi caps, Mercedes caps next year.

"So both of them were pretty good. But the headline that this is the best we can keep."

Antonelli agreed. "Monza, we clearly had the fastest car," he said. "We were just super quick, so of course it was incredibly special coming from the back. But it was also a track where it was relatively easy to overtake, and we were so quick.

"Definitely, Monza was a super-special one, and one that I will remember forever. But this one probably, in terms of execution, was better, because the way we built up and the way we built the performance throughout the weekend was very good."

Mercedes went to Austin with both cars in the new upgraded specification that had proved unconvincing, to say the least, when it made its debut in Malaysia two races ago.

There, Wolff said he thought it had made the car 0.3secs per lap slower. The team split the cars in Singapore to try to understand the package better, and then used it on both cars in Austin. Antonelli stuck it on pole and dominated the race. Russell's performance looked more like the one the car produced in Malaysia.

"The update we put on the car is difficult to operate," Wolff said. "And Kimi landed it.

"Maybe it's a bit harsh to say but I think his driving style just glues with the car. We saw that in qualifying yesterday where on his last lap he could have been another 0.15-0.2 secs up. And on the other side George just struggled so much. And I believe this is because the operational window of the car is so difficult."

When Antonelli clinches the title, he will become the first Italian to do so since Alberto Ascari in 1953. It's a remarkable statistic for a country which is so engrained in the sport, and it certainly resonates with his compatriots.

McLaren team principal Andrea Stella said: "As an Italian, wow, we need to go back to Ascari, the names that they created the inspiration for all of us. To see an Italian achieving this level of performance and results in Formula 1, that's particularly thrilling, as an Italian person in motorsport."

Stella's answer continued into an area that begins to explain the way in which he has proved so superior to Russell this year.

"Going more into the technical, and specifically this season, Kimi is a very interesting one to look at, because he pretty much attacks all the times," Stella said.

"You see how often he's just going off track, and you see his onboard (camera), he's pretty aggressive. But at the same time, this seems to be not only kind of an aggressive driving, or an attacking driving, but effective.

"And if we think how much we talk in these media sessions about the cars being difficult to drive consistently fast, it should be recognised how much he's been able to harness his driving style with what is required of the cars.

"But at the same time, almost contradicting what I'm saying, when is the time to bring home the result, he's been able to do it.

"So he's the deserving leader of this championship. He's writing an important piece of history for motorsport, because once he achieves the championship, he will be the youngest."

Antonelli will beat by more than three years the previous record for youngest winner of the championship, Sebastian Vettel in 2010.

As with the title itself, he is aware of the forthcoming achievement, but not letting it affect him.

"I'm going to approach it with the same mindset," he said. "Just trying to have as much fun as possible, trying to hopefully fight for another win.

"It would be best to finish on a high, and that's the goal. But I'm just going to try to enjoy the rest of the season from now on."