Lewis Hamilton's hopes of a podium finish in the Korean Grand Prix were wrecked by a rear anti-roll bar failure.
The former world champion's pace in the race dropped away shortly after the first pit stop, with him revealing on the radio that the car felt 'nervous.'
A post-race inspection of his McLaren has revealed that a rear anti-roll bar was to blame - which caused excessive tyre wear and compromised his chances of fighting at the front.
Hamilton eventually finished 10th, after being further hampered late in the race when he ran over some artificial grass which got wrapped around turning vanes by the sidepods.
Team principal Martin Whitmarsh said: "The roll-bar went, I think, about lap 18. By then he was fighting for third place and it fell away.
"It was absolutely destroying the tyres and his balance was gone. We did all we could at the stops but he was eating the tyres, so he had to do a three-stop with tyre pressure and front wing changes, and that is all we had to try and counter it.
"The car must have been horrendous to drive, so the fact that he was fighting there with Kimi for quite a few laps and then caught the two Toro Rossos at the end, was truly remarkable.
"Then, with four or five laps to go, when he should have been able to get the Toro Rossos, he picked up the turf - which finished the day off."
Although the result effectively ended Hamilton's world championship chances - as he now lies 62 points behind Sebastian Vettel with four races remaining - Whitmarsh was full of praise for his driver's efforts.
"He just was tenacious and a fighter, so it was a heroic drive from him," he explained.
"In the one sense of course I have to be bitterly disappointed with the afternoon, but on the other sense I have to be immensely proud of his job really, because in those circumstances it is very easy to not be fighting as hard as he was.
"You could see all the way through, with an awful balance to that car with a rear anti-roll bar failure, he fought with everyone and that is Lewis as a great, great racing driver. I am immensely proud of him."