Lewis Hamilton says winning his third world championship with an Ayrton Senna-style fighting performance made his triumph even sweeter.
The Mercedes driver bounced back from struggles in the wet, and bad timing with safety cars, to deliver victory and his third world title at Austin.
Speaking about the manner of his race, which reminded some of the way Senna often battled hard, Hamilton said: "That is important for me.
"Since karting days I have always been fighting through packs. Starting from the front is always a great thing, being in the lead and leading to the end is one thing. But to really fight through…
"I was struggling at the beginning, skating all over the place, and I fell back to fourth. Then I was back in second, then I was leading for a while, then I came back and Nico was ten seconds ahead.
"For me the most testing thing is that I never gave up. I kept believing I could win it and that is what I have had since I was a kid. Even if I started last, I believed that the potential was there."
Having matched Senna's tally of three world titles, Hamilton admitted that his lifetime achievement had been reached.
However, he has made it clear that it does not mean he will lack motivation to deliver more world championships in the future.
"The motivation part is really easy," he said. "I was born with it so it doesn't go away. I don't feel any worries about that, winning is winning, it never gets old.
"Obviously I still have the motivation for the next race. I want to win the next race, and it just rolls over. Everything I compete in, I want to win. I don't feel the need to go search for motivation at all.
"Niki [Lauda] told me about the day that he didn't enjoy it any more. So until that happens I guess I will keep going. I don't feel like this is it. I feel like this is the beginning. I will keep pushing."