Lewis Hamilton admitted that he spent virtually the whole of the United States Grand Prix haunted by memories of recent reliability issues with his Mercedes, and was worried that the car could once again suddenly fail without warning before the finish.
"The whole race I was concerned the car wasn't going to make it," he admitted after clinching a landmark 50th Grand Prix victory.
"Right up to the line, I was just in fear of hearing the same sound I heard in Malaysia so I'm grateful the car made it across the line.
"The whole race I couldn't get my mind off the reliability issues because we had another problem through qualifying yesterday.
"I was down on power to Nico today which would have cost me almost two seconds, so I was conscious sometimes down the straight I was half throttle, just please don't go, and fortunately it didn't."
Hamilton said that after the car made it to the end of the race in Austin without any problems, he felt a lot happier and more reassured than he had done in recent weeks following the heartbreak in Malaysia.
"I have a lot more confidence in its reliability, so it's going well and I just need to do my job and hope for the best," he said.
However, Hamilton is all too aware that the question of reliability might ultimately prove to be the deciding factor in this year's world championship battle with his team mate Nico Rosberg.
"Reliability is my, you know - I don't think he [Nico] has a single worry about that but I do, so that's really the only thing that can get in my way I think.
"I'm focussing on doing my job to the best of my ability. I can't control what's behind, so no point in hoping for anything, just hoping to do a better job on the weekend and have more weekends like this - that would be great."
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