Williams driver Pastor Maldonado has been penalised for causing the collision that took Lewis Hamilton out of the European Grand Prix.
The Venezuelan was given a 20-second penalty, which drops him from 10th to 12th place and out of the points.
The race stewards decided he had "failed to rejoin the track in a safe manner".
The incident happened when they were battling for third place with three laps to go in the race.
Maldonado tried to pass Hamilton's McLaren on the outside into Turn 12 but went off the track. Hamilton continued on the racing line and Maldonado hit him as he rejoined the track in the middle of Turn 13.
Hamilton refused to be drawn on the incident after the race.
"I don't really know what happened if I'm honest," he said. "I went in the corner and I didn't come out.
"It happened so fast I really don't remember what happened. All I remember was sitting in the wall with only a lap to go."
Hamilton had gone into the race leading the championship by two points from Ferrari's Fernando Alonso and three from Red Bull's Sebastian Vettel.
Alonso won the race, after Vettel retired from the lead with alternator failure, and the Spaniard now leads the championship by 20 points from Red Bull's Mark Webber, who was fourth in Valencia.
Hamilton is third, 23 points behind Alonso, with Vettel a further three adrift in fourth.
Hamilton's race was also afflicted by the latest in a series of pit-stop problems this season. At his second stop, he lost third place to Alonso, who had fought up from 11th on the grid, when his front jack failed.
Hamilton said: "Big congratulations to Fernando - it was very, very impressive race from him to come from all the way back in 11th place.
"[It was a] bad day in the office, but that's motor racing. We lost a lot of points today but fortunately for us a couple of the others who were fighting today, like Sebastian, weren't able to score - but it does make things a little tougher.
"You put your heart and soul into some things and, when you don't get the results you feel you worked for, it's very tough, but that's life."
Hamilton's team-mate Jenson Button finished eighth after starting ninth. He has scored only six points in the past five races and is now 62 points behind Alonso in the championship.
Button lost ground in the closing stages as Mercedes driver Michael Schumacher and Webber fought back up the field with fresher tyres.
"Twelve years of experience don't really help you this year," Button said.
"As a team we did a good job in terms of strategy. I don't think we were bad but we just didn't get lucky, like some people did by putting new tyres on at the end of the race, which is normally not what you would do at Valencia.
"The pace was there, we had some good moves but it just didn't fall our way. The car does feel good underneath me. I'm happy with it."