Sebastian Vettel's 36th career pole position put's him third on the all-time list behind Michael Schumacher and Ayrton Senna. Reuters Photo
The 25-year-old German, who needs to out-score nearest
rival Fernando Alonso of Ferrari by 15 points to become the youngest triple champion in F1 history, was fastest thoughout the session after topping the times in all three practice sessions.
He clocked a final best lap time of one minute and 35.657 seconds in the final seconds of a closely-fought hour of speed to leave nearest rival Lewis Hamilton adrift by a tenth of a second in his McLaren.
Vettel's Red Bull team-mate Mark Webber was third fastest ahead of Romain Grosjean of Lotus, but the latter will have to drop five places because his team fitted a new gearbox to his car before the session.
That meant that Alonso, who qualified ninth, will move forward one place to eighth on the grid for the penultimate race of the season at the new Circuit of the Americas, 25 kilometres out of downtown Austin.
It was Vettel's sixth pole this season and the 36th of his remarkable career.
To mark the occassion, he added a Texan lone star to his helmet design.
Kimi Raikkonen, who won the Abu Dhabi Grand Prix two weeks ago, was fifth for Lotus ahead of retirement-bound seven-time champion Michael Schumacher in his Mercedes.
Alonso's Ferrari team-mate Felipe Massa qualified seventh ahead of ever-improving Nico Hulkenberg of Force India, with Alonso ninth and Pastor Maldonado 10th for Williams.
Briton Jenson Button, in the second McLaren, failed to make the cut to the top-ten shootout after losing power due to a throttle pedal problem in Q2 on a day of clear skies and rising temperatures following a cold morning.