Lewis Hamilton missed the chance to chalk up his 100th victory but did take over the lead in the world championship as France's Esteban Ocon steered his way through a chaotic Hungarian Grand Prix on Sunday to collect his first-ever win.

After a tactical error dropped pole-sitter Hamilton to the last place, the Briton picked his way through the field, finally clawing his way past Ocon's Alpine teammate Fernando Alonso, to finish third behind the Frenchman and Sebastian Vettel in the Aston Martin.

However, Vettel was later disqualified when it was deemed his car had breached fuel regulations.

Hamilton 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!"

Max Verstappen's Red Bull was damaged in a first lap crash, which took out five cars, and he eventually finished 10th.

The Dutchman was then promoted to ninth after Vettel's expulsion leaving Hamilton to take an eight-point lead in the championship.

"Congratulations to the Alpine team and to Esteban for his first win -- he's been a shining star for a long time," said Hamilton who was booed again during his post-race interview by a section of the packed crowd who blame him for the crash at the British GP two weeks ago which took out Verstappen.  

"Today was definitely tough, we always make it difficult for ourselves.

"Crazy to think we were the only ones on the grid at the start, but these things happen and we learn from them. I gave it everything and I have nothing left in the end."

Mercedes also took over the constructors championship lead. Going into the summer break they are now 12 points ahead of Red Bull.

Turn 1 chaos

Two weeks after the controversial collision between Hamilton and Verstappen on the opening lap at Silverstone, there was early trouble again at the Hungaroring, this time prompted by Mercedes' Valtteri Bottas.

With the rain coming down, the Finn triggered a series of collisions on the opening turn which not only took him out of the race but accounted for Red Bull's Sergio Perez, Ferrari's Charles Leclerc, the Aston Martin of Lance Stroll and the McLaren of Lando Norris.

Bottas acknowledged he was at fault after being given a five-place penalty on the grid for the next race, the Belgian GP at Spa at the end of August.

"I think that's fair enough," said Bottas.

"I had a bad start and I lost the momentum. I misjudged the braking point and locked the wheels.

"I was responsible for hitting Lando and that meant he cut people off in front of him.

"It's not great for me and not great others. It's not like I did it on purpose."

Seven-time world champion 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 tyres to suit the improved weather.

Bizarrely, within one lap, Hamilton was at the back as Mercedes, having failed to switch his tyres, 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.