Australia’s Oscar Piastri was promoted to second when the disqualification was handed down.

Russell appeared to have won his third-ever F1 race, but two and a half hours after the chequered flag fell at the Spa-Francorchamps circuit, and with both Hamilton and Russell already heading back home to Monaco, the latter was thrown out of the official result.

Russell's Mercedes was found to be 1.5 kilograms underweight.

The stewards' decision provided Hamilton with his second win from his last three appearances, and a record-extending 105th of his career, but denied the Silver Arrows their first one-two finish since the penultimate round of the 2022 season in Brazil.

Reacting, Hamilton said: "I feel for George, and you don't want to win a race through a disqualification, but we have been back in the fight for victories in the past few races. It is incredibly competitive now."

Russell had just completed his media rounds when he was told his triumph was in grave danger.

"It is heartbreaking to be disqualified from today's race. It had been an unbelievable grand prix for us to make the one-stop strategy work," Russell said.

"Despite the disqualification, I am of course proud to have crossed the line first. It is also good that the team was still able to take the victory with Lewis."

With AAP.