Hamilton crashes in first practice in Japan
McLaren's title-contender Lewis Hamilton crashed in first practice at the Japanese Grand Prix after making his third mistake in as many races.
The Englishman lost control at Suzuka's tricky Degner corners, slid into the gravel and hit the barriers, damaging the left-hand side of his car.
"I was probably pushing too hard, too early," Hamilton said.
"It wasn't even that big an off. It's just unfortunate that the gravel is very slippery at that point."
Hamilton was unhurt in the accident, which happened about half-way through the session.
The 25-year-old has crashed out of the last two races and slipped from second to third in the championship.
Hamilton 'pushing too hard too early'
"I didn't get very wide and I couldn't stop the car," Hamilton added. "It was very slippery on the marbles and it was up on the gravel.
"They say bad things come in threes so hopefully it's over and done with."
McLaren team principal Martin Whitmarsh told BBC Sport the crash was driver error, adding Hamilton was "experimenting too early in the weekend".
The repairs meant he missed most of the second session and managed to get out on to the track only for the last nine minutes.
McLaren have a new rear wing in Japan, but Hamilton was unable to use it in second practice because his had been damaged. He will be able to use it on Saturday and Sunday, though.
McLaren off Red Bull pace - Button
"The guys are working very hard to make sure the fix the updated rear wing for tomorrow," Hamilton said.
"We don't have a lot of new parts - we have two new parts. I broke one of them in the crash so I couldn't use it in P2."
"We are going to have to work hard to keep the car on the track through P3 and then see how qualifying is but I believe it's going to be wet on Saturday so it's going to be difficult."
Hamilton's team-mate Jenson Button, also in championship contention, also went off the track at the same corner late in the session, but he managed to keep the car out of the barriers.
Button said: "It's very difficult to see the apex kerb, because of the colour, the sun is quite bright there and it's bumpy as well, so to focus is very tricky and our car is bouncing around a lot, especially though that corner, putting us off line and onto the kerb.
"We were very similar in what we did except that I was spinning before I got to the corner and Lewis carried through the corner speed and ended up in the wall."
Hamilton was second fastest behind Red Bull's Sebastian Vettel when he crashed.
The German retained top spot to the end of the session, ahead of his team-mate Mark Webber, the world championship leader. The two were first and second again in second practice.
Hamilton's crash appeared to be provoked when the car bottomed out on a bump on his way into the tricky 76mph corner.
That put him slightly off line, and the car slid off the track and into the gravel trap.
Hamilton was powerless to prevent it hitting the barriers a glancing blow, which tore the left-hand front wheel off the car and broke the front wing, which is a new design for this race as the team seek to make up lost ground in the championship.
Hamilton led the championship after winning the Belgian Grand Prix at the end of August.
But after crashing out of the last two races, both of which were won by Ferrari's Fernando Alonso, he is now 20 points behind Webber.
Alonso, meanwhile, has vaulted from fifth to second, 11 points adrift of the Australian.
Vettel and Button are fourth and fifth, with all five men covered by the points awarded for a win.