French driver Esteban Ocon took his first Formula One victory with Renault-owned Alpine on Sunday in a Hungarian Grand Prix that was stopped and re-started after first lap chaos.

Four-time world champion Sebastian Vettel was disqualified from the race and stripped of second place after his Aston Martin car was deemed to have insufficient fuel left after the race, the International Automobile Federation (FIA) said.

Lewis Hamilton of Mercedes was promoted to second place with Ferrari's Carlos Sainz filling out the podium.

For 24-year-old Ocon, who controlled the race from the front, it marked a maiden win in his 78th Grand Prix and a first victory for the new-look Alpine set-up.

"What a moment! It feels so good," said Ocon.

"It's fantastic; what can I say? Congrats to Fernando (Alonso) as well. I think the win is also thanks to him with the fight that he did. It's teamwork; it's been a fantastic day!"

The FIA released a statement five hours after the chaotic race ended at the Hungaroring.

"After the race it was not possible to take a 1.0-liter sample of fuel from car five," said the statement.

"The team was given several opportunities to attempt to remove the required amount of fuel from the tank; however, it was only possible to pump 0.3 liters out," the FIA statement said.

"Given this situation, car No. five is not in compliance with the requirements of FIA Technical Regulations." The decision robbed Aston Martin of what would have been just their second podium of the 2021 season following Vettel's runner-up spot in Azerbaijan.

In response, Aston Martin said, "The 18 points loss is disappointing for the team, but it doesn't take away from an otherwise flawless drive from Sebastian. Today, we showed that our car has strong race pace. Onwards and upwards."

Mercedes' Valtteri Bottas will have a five-place grid penalty at F1's next race in Belgium after the Finn triggered chaos and collisions on the opening lap of Sunday's Hungarian Grand Prix.

The race was halted after Bottas braked late and hit the back of Lando Norris's McLaren, which then smashed into the side of Max Verstappen's Red Bull and wrecked the race for both.

Stewards ruled Bottas caused an avoidable collision at Turn One, in wet and slippery conditions and handed him two penalty points.

"The Stewards took into consideration the track conditions; however, the driver of car 77 was fully to blame for the collision," they said in a statement.

The race was halted and restarted on Sunday with four drivers retiring – Bottas, Ferrari's Charles Leclerc, Aston Martin's Lance Stroll and Red Bull's Sergio Perez.

The Finn made a sluggish getaway and was passed by Norris and Verstappen, and he then braked way too late into the opening corner.

"I'm sorry guys," Bottas said over the radio.

Bottas' Mercedes teammate Hamilton, starting on pole for the 101st time in his F1 career, was ahead of the chaos in the rain and looked a nailed-on winner when he was on his own on the grid for the restart while the other cars were all changing tires to suit the improved weather.

Bizarrely, within one lap, Hamilton was at the back as Mercedes, having failed to switch his tires, called him in.

"I was telling the team how the track was during the lap, but they said the rain was coming when we got in the car, so I thought they had other information," said Hamilton after the race.

It marked the start of an epic race from the Briton, which might well have ended in his 100th GP win had it not been from superb defensive driving from 40-year-old Alonso, who prevented him closing on Vettel and Ocon.

Ocon was also untouched by the first lap chaos and was second at the restart. With Hamilton's plight, the Frenchman took over the race lead.

Hamilton retook the F1 championship lead from Red Bull's Verstappen.

(With input from agencies)