MONZA, Italy - World championship leader Lewis Hamilton on Saturday accepted he had made a mistake in gambling on his tyre choice during the rain-hit qualifying session for Sunday's Italian Grand Prix.

The error cost him a place in the top ten and condemned him to start from 15th on the grid, and a full nine places behind his nearest title rival, in the race.

Brazilian Felipe Massa, who was the beneficiary of Hamilton's loss of victory through a controversial stewards' decision last weekend at the Belgian Grand Prix, is just two points behind him in the championship and starts from sixth on the grid.

"It was a joint decision to go out on wet-weather tyres at the start of Q2 - partly mine and partly my engineers'," said Hamilton.

"We thought it was the right way to go at the time because it was getting drier, but the grip level was poor so I came in and switched to extremes.

"By the time I got out, it had begun to rain and I just missed the window when the track was at its fastest.

"It was very hard to pick out the braking points. It's the first time this has happened to me in Formula One, so I can't really complain.

"Tomorrow's another day. We still have a fighting chance to make our way up the grid. I'll be doing the best job I can."

McLaren boss Ron Dennis said: "The weather conditions made things difficult for everyone, not only us, and in addition to that we were caught out by a less-than-fully accurate weather forecast.

"As things turned out, there was only a narrow window of opportunity in which to cut a quick lap and things didn't fall kindly for Lewis. But the weather may be unsettled tomorrow, too, and if so, he should still be in a position to score a good result even though he'll be starting from a lower grid position than he would ideally have preferred."