Lewis Hamilton's hopes of a fifth successive British Grand Prix victory, and sixth in total, were dealt a heavy blow when he tangled at the start with Ferrari's Kimi Raikkonen and dropped to the back of the field.
Australia's Daniel Ricciardo has moved into third, from a grid start of sixth, on lap 17 of 52 in front of a 140,500 strong crowd at a sunny Silverstone on Sunday afternoon.
Ferrari driver Sebastian Vettal and Mercedes' Valtteri Bottas were in first and second place, respectively, while Ricciardo's Red Bull teammate Max Verstappen was in fourth.
Hamilton started on pole position for Mercedes, with Ferrari's championship leader Sebastian Vettel alongside making a clean getaway.
The Brit was slow off the line, however, and he and Raikkonen came together, with the Mercedes spinning around.
The Finn was handed a 10-second penalty by stewards for causing the collision.
"I think my car's broken," Hamilton told his team over the radio, also reporting damage to the right rear tyre although his engineer said the pressure was fine.
"I feel like I've lost half my floor," he added later.
"There may be some damage but we can't see much at the moment. We are still reviewing," the team assured him.
Hamilton is only a point behind Vettel after nine of 21 races and had hoped to retake the lead in front of his home crowd.
After nine laps he was already back up to seventh place, but 26.3 seconds adrift of Vettel.