Lewis Hamilton accepted the blame and apologised for his part in an opening lap crash with Fernando Alonso at Sunday's Belgian Grand Prix.
The seven-time world champion said he did not see Alonso who was in his blind spot, as he attempted to complete a passing move at Les Combes.
His Mercedes car's front right wheel hit the Alpine's front left, causing it to rise and then fall violently. The pair were unhurt and continued.
Moments later, however, he slowed to a halt in the middle of the track with his team telling him: "Stop, stop, stop", bringing to an end his run of five podiums and a perfect record of race finishes this season.
"It's definitely my fault," said Hamilton.
"I didn't see him. I've apologised. He was in my blind spot. So it's unfortunate... I mean, it's motor racing, I gave it everything.
"I tried to overtake on the outside into turn five. Just didn't leave quite enough space and I paid the price for it. It wasn't intentional. It just happened."
An angry Alonso ranted on Alpine team radio at the time: "What an idiot. He closed the door from the outside. I mean, we had a mega-start but this guy only knows how to drive starting first."
Alonso was more restrained after the race and said he was happy to hear of Hamilton's explanation and acceptance of the blame.
"I think he thought that I wasn't there anymore," said Alonso. "So I don’t think that it's a mistake – it's just that in the heat of the moment you try to take the slipstream, brake late and turn in.
"Sometimes, you don't measure the cars completely, where everybody is, but I don't know... I normally take more care.
"It was his mistake to close the door like that."
Alonso added that Les Combes was a notably tricky corner.
"We have seen that many, many times here. It happened to him with (Nico) Rosberg a few years ago, so this time it is the same thing."
He said he agreed with the stewards' decision not to penalise Hamilton.
"It was a first lap incident," he said. "These things happen. In that corner, especially, there are a lot of things that are going on.
"People normally cut the corner in (turn) six and re-join the track in seven.
"So it's a tricky part of the circuit for sure. It was a racing incident and there's nothing more to say."
Shortly after, Nicholas Latifi (Williams) took out the Alfa Romeo of Hamilton's old Mercedes team-mate Valtteri Bottas as up ahead Max Verstappen swept away his rivals to head a Red Bull 1-2.