Sebastien Buemi accepted the blame for the tangle with Timo Glock that ended both their races in Korea.
The Toro Rosso driver caused one of the event's multitude of safety car periods when he slithered into the Virgin at the end of the circuit's long straight, ripping a wheel from his car and coming to rest on the edge of the run-off area.
Buemi was trying to make up ground having made an early change to intermediate tyres, and was confident he was on course to earn points, having been racing with the Saubers - which both scored - when he crashed.
"I am disappointed with my race as I think there was plenty of potential for me this afternoon," said Buemi.
"I was running as high as seventh before the accident as everyone had stopped to change tyres. My pace was good and I was able to pass [Kamui] Kobayashi, [Nick] Heidfeld and the Lotus and Virgins and it was going really well. We lost the chance to score some real points today."
He admitted he had just lost control when trying to pass Glock.
"I braked late and locked the front wheels, so I could not turn and ended up going straight on and hitting Timo. I am sorry for him," said Buemi, who had also sent Heikki Kovalainen spinning in an earlier clash.
Toro Rosso then lost out on a single point late on when Williams's Nico Hulkenberg passed Buemi's team-mate Jaime Alguersuari for 10th on the final lap.
"We missed out on a good opportunity to score points today, so I am very disappointed, because just getting to the finish was an achievement given how many cars did not manage to do that," said Alguersuari.
"I obviously lost out most during the pitstop, when a technical problem meant I went into the pits in ninth place and came out in 15th place.
"Throughout the race, I lacked speed down the long straights and that is why it was hard to move back up the order, then at the end, when I had finally managed to get into the points, I could do nothing against Hulkenberg, who was faster in a straight line and was on new tyres.
"It is hard to be competitive when you lack the top speed, because it also means we ran less downforce than others in order to make up for that, so it is harder to manage the tyres in this situation."