The McLaren driver came into contact withSauber’s Kamui Kobayashi into the braking zone for Les Combes, having just passed the Japanese up the hill for fourth position.
The collision made Hamilton’s car snap left and hit the barrier hard before careering up the run-off area.
After initially being upset, Hamilton later admitted on his Twitter feed that he had made a mistake.
“After watching the replay, I realise it was my fault today 100 per cent,” said Hamilton. “I didn’t give Kobayashi enough room though, I thought I was past.”
Kobayashi had earlier insisted that the British star was at fault, claiming that he had nowhere to go.
“I knew that I could not fight because he was much quicker than me,” said the Japanese driver.
“He overtook me and was using the DRS rear wing, which I didn’t. I was just using KERS, but we were running very low downforce and that’s why I caught him up again.
“At the end of the straight, I was on the left and he was in the middle of the track. He came back and we had contact.
“If you look at the replay, I was always following the white line. I didn’t change my line at all.
“I don’t know what I needed to do. Maybe I needed to go into the gravel for him? He just had to stay in the middle of the track and not come back.”
Hamilton added that he thought it would have been difficult to contend for the win in any case, and said that he was struggling to follow the two Red Bulls and Fernando Alonso’s Ferrari ahead of him.
“I think we were struggling,” he said. “For whatever reason we were massively slow on the straight, massively, massively slow and I guess that’s really what got us in the position really.
“Everyone was just pulling away from me on the straights and I was only able to keep up on the infield. I think we probably had a little bit too much downforce on.
“Nonetheless we were in a good position still we were still able to challenge and I got past one of the Ferraris. We maybe have been able to have at least got a podium.”
Eurosport / AutoSport