Daniel Ricciardo has qualified third fastest for the US Grand Prix with Formula One world champion Lewis Hamilton claiming pole ahead of Mercedes teammate Nico Rosberg.
Hamilton, 33 points behind the German Rosberg with four rounds remaining, has won three of the past four races in Austin but had never before managed to seize top slot on the starting grid in Texas.
The Briton's fastest lap of one minute 34.999 seconds was 0.216 quicker than Rosberg, who starts alongside him on the front row, and also the quickest yet at the Circuit of the Americas.
Australian Ricciardo finished one ahead of Dutch Red Bull teammate Max Verstappen joining him on the second row.
Winning all of the last four races may not be enough for Hamilton, with Rosberg sure to clinch the title if he finishes second in them, and the Briton has suffered poor starts and reliability issues.
With Mercedes making a precautionary change to the fuel system on his car overnight, mindful of the engine failure that cost him 25 points in Malaysia, Hamilton had another scare when he slowed after his first quick lap of the final session.
"Weird shift up to seventh (gear)," the champion told the team over the radio before putting it all together with an even quicker lap after Rosberg had gone top.
The pole was the 58th of the 31-year-old's career, leaving him seven short of boyhood idol Ayrton Senna and 10 behind seven-times champion Michael Schumacher's record.
"I feel amazing. It's my first pole here so it's been many years of trying and a lot of great people have tried to help me get that. I want to say a big thank you to all the crowd," said Hamilton.
Rosberg, chasing his 10th win of the season on Sunday while Hamilton has six, said he had lost speed in the first sector but played down the significance of the Saturday duel.
Ferrari's Kimi Raikkonen qualified fifth with German teammate Sebastian Vettel sixth.
Germany's Nico Hulkenberg will line up seventh for Force India with the two Williams cars of Valtteri Bottas and Felipe Massa behind.
For the first time in 30 years a US-owned team will compete on home soil but Haas F1 face a battle to get into the points after Mexican Esteban Gutierrez qualified 14th and Frenchman Romain Grosjean 17th.
