AUSTIN (Texas) • Fear of failure haunted Lewis Hamilton at the US Grand Prix on Sunday, even as he sped towards victory and membership of Formula One's super-elite club of 50 race winners.

When the three-time world champion was informed that he had joined greats Michael Schumacher (91 race wins) and Alain Prost (51) as only the third driver to reach the half-century, the Briton sounded surprised.

Most of his attention, on what to all appearances was a dominant afternoon in the Texas sunshine, was spent fretting about whether a possible engine failure would deal another devastating blow to his battered title hopes.

"In the cockpit all I could think about was the car making it to the end," Hamilton told reporters after the champagne had been sprayed, team photographs taken and autographs signed.

"Nothing else. It was the whole race. It was the longest afternoon that I've had probably that I can remember really in my career, just hoping that the car makes it to the end.

"Gearbox. You're feeling all the vibrations of the engine through the rev range and gear shifts.

"Every single lap I was thinking something might happen... when I get on that back straight I'm petrified. I was honestly just haunted by that.

"When I (crossed) the line I was so happy, just rubbing the cockpit, thank you for getting me there."

In Malaysia two races earlier, Hamilton had been enjoying a similarly commanding afternoon when the engine suddenly failed and 25 points disappeared in smoke.

With them, he would now be leading the championship rather than fighting 26 points behind German team-mate Nico Rosberg with three races left.

Rosberg, who finished second in Austin ahead of Red Bull's Daniel Ricciardo, is still the title favourite, only needing two second-place finishes and a third place even if Hamilton wins all the remaining races.

"All I can do is my best, Nico has been driving fantastically well, so the battle will continue. I will be going for it," the Briton said.

Hamilton also spoke about his "surreal" feelings after becoming only the third F1 driver to win 50 races.

"It's been a long time coming. I've had lots of ups and downs and had some great opportunities from gifted people who helped me get here today," the 31-year-old said.

"It's a very surreal feeling. I can't believe it.

"Hopefully it will bring on bigger and better things."

Rosberg told reporters after the race that he was aware of the championship points position and his clear lead but that he was not satisfied about finishing second to Hamilton.

"I wanted to win this race and I want to do it well, but it did not work out that way this time," said the German, who is also 31.

"I'm aware of the situation and that I lead by 26 points with three races to go and it's nice to be in that position.

"I am only going to approach it one way and that is to try and win each race at a time - so I will be aiming to win next week's race in Mexico."

If Rosberg wins in Mexico on Sunday and Hamilton fails to score a point, then the German will be crowned world champion for the first time.

REUTERS, THE GUARDIAN, AGENCE FRANCE-PRESSE