Lotus driver Kimi Raikkonen admitted he made a mistake during qualifying Saturday for the Korean Grand Prix, leaving him only 10th fastest and outgunned by team-mate Romain Grosjean.
The former world champion Raikkonen, who will make a high-profile switch to Ferrari next season, locked up at a turn, then repeated the error soon afterwards.
"I made a mistake on my only set of new tyres in the final qualifying session," the straight-talking Finn said.
"So my lap wasn't fast enough for a better position, which eventually meant I ended up 10th and will start from ninth position tomorrow (because of a penalty to Mark Webber).
"We've had a bit of understeer in the car so I've struggled a little all weekend.
"If you look at the long run pace yesterday we should have a stronger race, but obviously we have to see how the weather turns out."
Grosjean is in good form and qualified fourth, but like Raikkonen moves up a place on the grid thanks to the 10-place penalty handed to Webber after the last race.
Frenchman Grosjean, who has outperformed his more famous partner in recent weeks, said: "Our aim was to be up there fighting with the Mercedes today and that's exactly where we were.
"The Red Bulls were always going to be quick, so to be reasonably close to them in terms of the times is not too bad.
"Gaining a place on the grid just because another driver has been penalised is not how you want to move forwards, but I've had to cope with it before myself and it's part of the sport."
Red Bull's Sebastian Vettel is on pole for Sunday's race, with Mercedes' Lewis Hamilton joining him on the front row of the grid.