MEXICO CITY, Nov 1 - A tearful Kimi Antonelli became Formula One's youngest world champion at 20 years and 68 days old on Sunday when he finished third for Mercedes in a red-flagged and restarted Mexico City Grand Prix won by Red Bull's Max Verstappen.

The first Italian champion since 1953 sobbed with joy over the team radio as he took the chequered flag at the high-altitude Autodromo Hermanos Rodriguez, with his overall lead now an unassailable 119 points.

Ferrari's Lewis Hamilton started from pole position and took a close second place -- after clashing with teammate Charles Leclerc -- on an afternoon of drama with two safety cars, multiple crashes and an agonising 33-minute halt with 25 of the 71 laps remaining.

"Get in there, Kimi. Champion of the world," said his race engineer Peter Bonnington, a regular target for the young driver's practical jokes.

"We did it thank you so much," gasped the Italian, whose parents and sister were there to embrace him when he stepped out of the car. He was then mobbed by his pit crew.

The previous youngest champion was Germany's Sebastian Vettel, who took the first of his four with Red Bull at 23 years and 134 days in 2010.

"I’m speechless. I’m trying to process what has just happened," said Antonelli in comments to the crowd. "It’s been an incredible season, and to share this podium with Max and Lewis is truly incredible. And looking forward to some more battles in the future.

"This weekend I did feel a bit more tense, but I’m just so happy that we got it done, and now we can enjoy the rest of the season," he added, with an Italian flag wrapped around his shoulders on the podium and spraying the champagne with abandon.

The last Italian champion was Alberto Ascari, 73 years earlier.

Leclerc finished fourth, McLaren's outgoing champion Lando Norris was fifth and Antonelli's teammate George Russell only sixth in a race he had to win to have any chance of staying in contention.

That also meant Verstappen went second in the overall standings, with Hamilton third and pre-season favourite Russell plummeting to fourth and 130 points behind Antonelli.

McLaren's Oscar Piastri was seventh in the race, ahead of Alpine's Franco Colapinto and Racing Bulls' Liam Lawson. Alpine's Pierre Gasly completed the top 10. REUTERS