Germany's Nico Rosberg put Mercedes on pole position for the US Formula One Grand Prix with championship leading team mate Lewis Hamilton qualifying second.
Mercedes-powered Williams filled the second row with Finland's Valtteri Bottas third fastest and Brazilian Felipe Massa fourth.
Hamilton leads Rosberg by 17 points with three races, and 100 points remaining. The Briton has won the last four grand prix and is chasing his 10th victory of the season.
If the pair finish one-two on Sunday, as looks more than likely, Mercedes will equal McLaren's record of 10 in a season set with Alain Prost and the late Ayrton Senna.
The pole was the ninth of the season for Rosberg and 13th of his career.
Hamilton, who had been quickest in all three practice sessions and the first phase of qualifying, had tyre and brake issues when it mattered most and expressed some concern for Sunday.
That race comes on the sixth anniversary of his 2008 world championship triumph in Brazil.
Australian Daniel Ricciardo qualified fifth for Red Bull while his team mate and 2013 winner Sebastian Vettel starts from the pitlane after exceeding his engine allocation for the season.
Ferrari's Fernando Alonso qualified sixth.
There was also a ray of hope for beleaguered Sauber, who have yet to score a point this year, with Germany's Adrian Sutil qualifying 10th.