The celebrations will run long and hard in the Mercedes camp after the crowning of 20-year-old Kimi Antonelli as the youngest ever world champion, but there is one man for whom the Italian's joy will be tinged with regret.
After all, this season was supposed to be all about George Russell.
After dominating early season testing, Russell went into the campaign as universal favourite to take the title, the heir to Lewis Hamilton at Mercedes ready to assume his place in the pantheon.
That status was reinforced by an imposing victory in the opening race in Australia. Since then, however, that early optimism has turned to ashes as he has had to watch the young pretender steal in and claim his crown.
Russell needed to win in Mexico to have any hope of stalling the young Italian but a faltering sixth place, which included a 10-second penalty for bumping Isack Hadjar, was nowhere near good enough.
But it summed up a disappointing season of mistakes and bad luck.
"I've probably learned more about myself this year than I would have liked to, in all honesty," the Englishman said before the race in Mexico.
"The highs and lows you go through in sport are immense and that's because we all care so much for what we're doing."
Russell has always been candid and he will undoubtedly think back to a perfect opening weekend in Melbourne and wonder how it all went so badly wrong.
He dominated qualifying, taking pole position with three-tenths of a second in hand over Antonelli, and followed up by winning the race with a three-second gap to his teammate with the rest flailing in his wake.
Was there a touch of complacency, however, behind his smile on the podium?
"After his performances in Australia and given the gap to the other teams, he already pictured himself as world champion. Maybe he got ahead of himself a bit too soon," a paddock insider told AFP.
Fourth in the 2025 championship with twice as many points as Antonelli, who was in his rookie F1 season, the 28-year-old Englishman cannot have foreseen such a tussle with his teammate.
Not that it was much of a tussle: Antonelli has proved stronger in his head and on the track all season.
'STRUGGLING'
Things quickly went off the rails for Russell.
Despite a pole position and a sprint win at the second event in China, Russell then watched, powerless, as Antonelli delivered a masterclass to claim his first ever grand prix win.
It was the first of five consecutive wins for the Italian which left his teammate reeling.
After his victory in early June in Monaco, the sixth round of the season, Antonelli already held a 68-point lead over a disheartened Russell, who was running third behind Hamilton.
Hit with two penalties in Monaco, where he dropped from third to 12th place right at the end of the race, the Englishman fumed.
"I'm beyond frustrated and I'm struggling to understand how this season is unfolding," he said.
Russell has certainly had his share of misfortune this season, as he was forced to retire in Canada and Malaysia due to technical problems, and in Belgium after being hit by Hamilton.
Antonelli, by contrast, has on several occasions benefited from safety car interventions, as in his victory in Madrid.
But Russell seemed to give in far too early. After his retirement at Spa, he said he felt "numbed by disappointment", and as early as the summer break he considered the gap to his teammate almost impossible to close.
There were glimmers of the old Russell as he pulled out superb drives to win in Austria and Azerbaijan but by then it was all but over with the gap between the two drivers sharply illustrated by the Italian GP at Monza.
Russell qualified second while Antonelli was forced to begin in 19th. The race was Russell's to lose, which he did.
He finished second, nearly four seconds behind the winner, Antonelli, who had picked his way through the field in one of the all-time great drives.
In Austin last week, before the US Grand Prix, a disarmingly straight Russell said what everyone has been thinking: "I haven't been up to the task."
No one can argue with that but ahead of Mexico, Russell hinted that his best is yet to come.
"I remind myself that I'm 28 and I see Lewis (Hamilton) still competing extremely well at 41 and Fernando (Alonso) at 45," he said.
"And you know Lewis won the majority of his titles in his thirties so this year is absolutely not going to define my career as a whole.
"It's not going to break me. If anything, it's going to make me stronger."